Chemistry Straighterline
1. A compound containing chromium and silicon contains 73.52 mass percent chromium. Determine its empirical formula Cr3 Si2 100.00L - 73.52= 16.48
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1. Hydrochloric acid can be prepared by the following reaction: 2NaCl(s) + H2So4(aq)---->4HCl (g) + Na2SO4 (s) How many grams of HCl can be prepared from 2.00 mol H2SO4 and 150g NaCl? 93.5
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1. Phosphine, an extremely poisonous and highly reactive gas, will react with oxygen to form tetraphosphorus decaoxide and water (balance the equation) PH3 (g) + O2 (g)-----> P4O10(s) + H2O (g) Calculate the mass of P4O10(s) formed when 225g of PH3 reacts with excess oxygen. 470g
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1. Phosphorus pentachloride, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of phosphorus pentachloride. 0.186 mol
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1. Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood, pulp and textiles). SO2(g) + 2Cl2 (g) -----> SOCl2 (g) + Cl2O (g) If 0.400 mol of Cl2 reacts with excess SO2, how many moles of Cl2O are formed? 0.200 mol .4mol Cl2 x 1mol O2/2 mol Cl = .2m
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1. What is the percent carbon in CH3 CH2 OH? 52%
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Which of these is a weak acid? E A. HNO3 B. H2SO4 C. HBr D. HI E. H2S Answer: E
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For which of these species is the best description of the bonding provided by two or more equivalent resonance structures? A. HCO2- b. SCN- c. CNO- d. N3- e. CO2
A
The oxidation number of Fe in K3Fe(CN)6 is +3 +2 +1 -3 -4
A
Which gas has molecules with the greatest average molecular speed at 25°C? CH4 Kr N2 CO2 Ar
A
Which of these compounds is an acidic oxide? A. P4O10 B. MgO C. Fe2O3 D. K2O E. Cr2O3
A
The oxidation number of N in N2H4 is: M A. +4 B. ─ 4 C. +2 D. ─ 2 E. 0
Answer: D
The oxidation number of Cl in ClO4─ is: H A. ─ 1 B. +1 C. +3 D. +5 E. none of these
Answer: E
Define specific heat
Answer: The amount of heat required to raise the temperature of one gram of the substance by one degree Celsius.
The number of resonance structures for the sulfur dioxide molecule that satisfy the octet rule is a. 1. B. 2. c. 3. d. 4. e. none of these
B
Which of the following represents a metal displacement reaction? 2NaN3(s) 2Na(s) + 3N2(g) Fe2O3(s) + 2Al(s) 2Fe(s) + Al2O3(s) 3NO2(g) + H2O(l) 2HNO3(aq) + NO(g) 2P(s) + 3Cl2(g) 2PCl3(g) 2ZnS(s) + 3O2(g) 2ZnO(s) + 2SO2(g)
B
Which of these compounds is a weak electrolyte? A. HCl B. NH3 C. C6H12O6 (glucose) D. N2 E. KCl
B
Which element has the following ground-state electron configuration? 1s22s22p63s2 A. Na B. Mg C. Al D. Si E. Ne
B Mg
Identify the oxidizing agent in the following chemical reaction. 2MnO4- + 5H2SO3 2Mn2+ + 5SO42- + 4H+ + 3H2O A) H+ B) SO42- C) MnO4- D) Mn2+ E) H2SO3
C
The electron configuration of a ground-state vanadium atom is A. [Ar]4s24d3. B. [Ar]4s24p3. C. [Ar]4s23d3. D. [Ar]3d5.
C. [Ar]4s23d3.
What is the name of BBr3?
C. boron tribromide
What is the formal charge on phosphorus in a Lewis structure for the phosphate ion that satisfies the octet rule? a. -2 b. -1 c. 0 D. +1 e. +2
D
How many sulfur atoms are present in 25.6 g of Al2(S2O3)3? A. 0.393 B. 6 C. 3.95 1022 D. 7.90 1022 E. 2.37 1023
E
What is the formal charge on sulfur in the best Lewis structure for the SCN- (thiocyanate) ion? a. +2 b. -2 c. +1 d. -1 E. 0
E
Which of the following ions occurs commonly?
E. O2-
Define and illustrate with an example the difference between an electrolyte and M nonelectrolyte.
(answers will vary) An electrolyte is a substance that will dissolve in water and break up into ions so the solution can conduct electricity. An example is Sodium hydrogen carbonate. A nonelectrolyte is a substance that does not break up into ions when dissolved in water and the resulting solution does not conduct electricity. An example is sugar.
Find H°rxn for the reaction 2Na(s) + 2H2O(l) 2NaOH(aq) + 2H2(g). [H°f (NaOH(aq)) = -426.8 kJ/mol; H°f (H2O(l)) = -285.5 kJ/mol]
-282.6 kJ
1. Aluminum oxide, Al2 O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51g of Al2 O3. 0.4660 mol
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1. Aluminum sulfate, Al2(So4)3, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molecular or formula mass. 342.15 g/mol
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1. Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis). Al(s) + Br2 (l)----->Al2Br6 (s) (unbalanced) 2 3 How many moles of Al are needed to form 2.43 mol of Al2Br6? 4.86 mol 2.43 mol Al2Br6 x 2mol Al/1mol Al2Br6
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1. Ammonia will react with flourine to produce dinitrogen tetrafluoride and hydrogen flouride (used in production of aluminum, in uranium processing, and in frosting of light bulbs) 2NH3(g) + 5F2 (g)-----> N2F4 (g) + 6HF (g) How many moles of NH3 are needed to react completely with 1.6 mol of F2? 5.44 mol
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1. Balance the following equation using the smallest set of whole numbers, then add together the coefficients. Don't forget to count coefficients of one. The sum of the coefficients is ___SF4 + ___H2O ----> ___H2SO3 +___HF
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1. Balance the following equation: C8H18O3(l) + O2(g)---->H2O(g) + CO2(g) C8H18O3(l) + 11O2(g)-----> 9H20(g) + 8CO2(g)
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1. Balance the following equation: Ca3(PO4)2(s) + SiO2(s) + C(s)----->CaSiO3(s) + CO (g) + P4(s) 2Ca3(PO4)2(s) + 6SiO2(s) + 10 C(s)----->6CaSiO3(s) + 10CO(g) + P4(s)
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1. Balance the following equation: UO2(s) + HF(l)---->UF4(s) + H2O UO2(s) + 4HF(l)----->UF4(s) + 2H20(l)
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1. Calculate the molecular or formula mass of rubidium carbonate, Rb2CO3 230.94 g/mol
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1. Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH)2 0.305 mol
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1. How many grams of nitrogen are requires to react with 2.79g of hydrogen to produce ammonia? 13.0 g o N2 + 3H2----> 2NH3 o 2.79gH2 x 1mol H2/2.79g x 1molN2/3molH2 x 28gN2/1molN2
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1. How many grams of water could be made from 5.0 mol H2 and 3.0 mol O2? 90 g
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1. Tetrasulfur dinitride decomposes explosively when heated. What is it's formula? S4N2
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1. What is the coefficient of H2SO4 when the following equation is properly balanced with the smallest set of whole numbers? __Ca3(PO4)2 +___H2SO4 ----> ___CaSO4 + ___H3PO4
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1. What is the limiting reactant when 13.9g of oxygen react with 33.7g of calcium to produce calcium oxide and how many grams of calcium oxide are produced? Calcium is the limiting reactant and 47.1g of calcium oxide are produced
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1. what is the limiting reactant when 3.41g of nitrogen react with 2.79g of hydrogen to produce ammonia and how many grams of ammonia are produced? Nitrogen is the limiting reactant and 4.15g of ammonia are produced.
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25.0 mL of a 0.175 M solution of KOH is diluted with pure water to a final M volume of 750.0 mL. What is the final molarity of the KOH solution? A. 0.00583 M B. 0.0163 M C. 0.0333 M D. 0.229 M Answer: A
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4.64 Complete and balance the following redox equation with the smallest set of whole-number coefficients M possible. What is the sum of the coefficients? Bi(OH)3 + SnO2 2 ─ Bi + SnO32 ─ (basic solution) A. 32 B. 25 C. 16 D. 13 E. none of these Answer: D
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Complete and balance the following half-reaction. M ClO─ + e─ Cl─ (basic solution) The balanced half-reaction will show which of the following: A. two hydroxide ions on the right side B. one electron on the left side C. six H+ ions on the right side D. six H+ ions on the left side E. two water molecules on the left side Answer: A
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Complete and balance the following redox equation with the smallest set of whole M number coefficients possible. What is the sum of the coefficients? (Remember the coefficients equal to one.) HI + HNO3 I2 + NO (acidic solution) A. 5 B. 7 C. 14 D. 17 E. none of these Answer: D
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Complete and balance the following redox equation with the smallest set of whole- M number coefficients. Now sum the coefficients of all species in the balanced equation. Remember the coefficients equal to one. The sum of the coefficients is: BrO3─ (aq) + Sb3+(aq) Br ─ (aq) + Sb5+(aq) (acidic solution) A. 4 B. 12 C. 13 D. 17 E. none of these Answer: D
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Complete and balance the following redox equation with the smallest set of whole-number coefficients M possible. What is the sum of the coefficients? MnO4─ + Br ─ Mn2+ + Br2 (acidic solution) A. 6 B. 17 C. 21 D. 29 E. 43 Answer: E
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Complete and balance the following redox equation with the smallest set of whole-number coefficients M possible. What is the sum of the coefficients? Br2 BrO3─ + Br─ (basic solution) A. 9 B. 12 C. 18 D. 21 E. none of these Answer: C
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Complete and balance the following redox equation. What is the coefficient of H2O M when the equation is balanced with the set of smallest whole numbers? MnO4─ + I ─ MnO2 + IO3─ (basic solution) A. 1 B. 2 C. 4 D. 10 E. none of these Answer: A
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Complete and balance the following redox equation. When balanced with M whole number coefficients, the coefficient of S is: H2S + HNO3 S + NO (acidic solution) A. 1 B. 2 C. 3 D. 5 E. 6 Answer: C
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Complete and balance the following redox reaction with the smallest set of whole-number coefficients. M When correctly balanced the sum of all the coefficients in the equation will be: (Recall, the absence of a coefficient is understood to be a 1) PbO2(s) + Cl─ Pb2+ + Cl2(g) (acidic solution) A. 2 B. 4 C. 5 D. 9 E. 11 Answer: E
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Complete and balance the following redox reaction. What is the coefficient of H2O M when the equation is balanced with the smallest whole number coefficients? MnO4─ + SO32 ─ Mn2+ + SO42 ─ (acidic solution) A. 3 B. 4 C. 5 D. 8 E. none of these Answer: A
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Complete and balance the following redox reaction. What is the coefficient of H2S M when the equation is balanced with the set of smallest whole numbers? H2S + MnO4─ Mn2+ + SO42 ─ (acidic solution) A. 1 B. 2 C. 4 D. 5 E. none of these Answer: D
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Complete and balance the following redox reaction. What is the coefficient of OH─ M when the equation is balanced with the set of smallest whole numbers? MnO4─ + I ─ MnO2 + IO3─ (basic solution) A. 1 B. 2 C. 4 D. 10 E. none of these Answer: B
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Consider the solution reaction AlCl3 + 3AgNO3 3AgCl + Al(NO3)3. M What volume of 0.100 M AlCl3 will exactly react with 55.0 mL of 0.162 M AgNO3? A. 89.1 mL B. 9.90 mL C. 46.2 mL D. 29.7 mL Answer: D
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Describe the procedure used to make 3.0 liters of a 2.0M KCl solution, starting H with solid KCl. Answer: a. Determine the molar mass of KCl, which is 74.55 g/mol. b. Weigh out 447.3 g of KCl and dissolve to form exactly 3 liters of solution.
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During a titration the following data were collected. A 10 mL portion of an M unknown solution was titrated with 1.0 M NaOH. It required 40 mL of the base to neutralize the sample. (a) What is the molarity of the acid? (b) How many moles of acid are present in 2.0 liters of this unknown solution? Answer: a. 4 M b. 8 mol
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During a titration the following data were collected. A 50 mL portion of an HCl M solution was titrated with 0.50 M NaOH. It required 200 mL of the base to neutralize the sample. How many grams of acid are present in 500 mL of this acid solution? Answer: The acid is 2 M. 36.5 g of HCl
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From the following equation, we can deduce that six hundred P4O10 molecules M would react with one hundred H2O molecules. P4O10(s) + 6H2O(l) 4H3PO4(aq) Answer: F
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Identify each of the following as either good or poor conductors of electricity. M a. CaSO4 b. Pb(C2H3O2)2 c. glacial acetic acid d. gasoline (C8H18) Answer: a. good b. good c. poor d. poor 4.114
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Identify the Bronsted/Lowry acid in the following reaction. M NH3 + H2O NH4+ + OH─ Answer: H2O
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Identify the oxidizing agent in the following reaction: H 2MnO4─ + 5H2SO3 2Mn2+ + 5SO42 ─ + 4H+ + 3H2O A. MnO4─ B. H2SO3 C. Mn2+ D. SO42 ─ E. H+ Answer: A
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Identify the oxidizing agent in the following reaction: 2 Na(s) + H2(g) 2 NaH(s) M A. Na(s) B. NaH(s) C. H2(g) Answer: C
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Identify the reducing agent in the following reaction. M Cd + NiO2 + 2H2O Cd(OH)2 + Ni(OH)2 A. Cd B. NiO2 C. H2O D. Cd(OH)2 E. Ni(OH)2 Answer: A
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Identify the reducing agent in the following reaction: H 5Fe2+(aq) + MnO4─(aq) + 8H+(aq) 5Fe3+(aq) + Mn2+(aq) + 4H2O(l) A. Fe2+ B. MnO4─ C. H+ D. Mn2+ E. Fe3+ Answer: A
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If 145 g of potassium nitrate were added to water to make 1500 mL of solution, M what would be the molarity of the resulting solution? Answer: .956 M
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If 40.0 mL of H2SO4 solution reacts with 0.212 g of Na2CO3, what is the M molarity of the H2SO4 solution? Na2CO3 + H2SO4 Na2SO4 + CO2 + H2O A. 0.50 M B. 0.10 M C. 0.20 M D. 0.40 M E. 0.050 M Answer: E
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In the following reaction, which species is being reduced? M FeBr3 + 3Cl2 2FeCl3 + 3Br2 A. the Cl in Cl2 B. the Fe in FeBr3 C. the Br in FeBr3 D. This is not a redox reaction. Answer: A
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In which of the compounds below is nitrogen in the +1 oxidation state? M A. N2O4 B. HNO3 C. N2 D. N2O E. none of these Answer: D
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Most compounds containing chlorides, bromides, and iodides are soluble except E those of Ag+, Hg, and Pb2+. Answer: T
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Predict the products of the following displacement reaction. M Fe(s) + CuSO4(aq) A. CuS(s) + Fe2SO4(aq) B. Fe(s) + Cu(s) + SO4(aq) C. Cu(s) + FeSO4(aq) D. FeCuSO4 E. FeO(s) + CuSO3(aq) Answer: C
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Silver chloride (AgCl) has an extremely low solubility in water; therefore, it is a E weak electrolyte. Answer: F
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Solutions of BaCl2(aq), Na2SO4(aq) and KNO3(aq) are mixed together. M What compound is likely to precipitate from the solution? A. NaNO3 B. Ba(NO3)2 C. BaSO4 D. KCl E. K2SO4 Answer: C
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Sugar dissolves in water, therefore it is a strong electrolyte. E Answer: F
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The following equation is balanced. M Ca(NO3)2(aq) + H2SO4(aq) CaSO4(s) + 2HNO3(g) Answer: T
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The solubility of Ba(NO3)2 is 130.5 g per liter at 0°C. How many moles of H dissolved salt are present in 4.0 L of a saturated solution of a Ba(NO3)2 containing 130.5 g/L at 0°C? Answer: 2.0 mol
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The water solution found in cells and in blood makes up approximately 80% of the mass of the human body. This solution has a concentration of 0.21 M NaCl and has a density of 1 g/mL. How many pounds of salt are present in an 180 lb adult? Answer: 1.77 lbs (802.5 g)
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We balance chemical equations because they obey the law of definite proportions. M Answer: F
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What element is oxidized in the following reaction? M 3Cu + 8HNO3 Cu(NO3)2 + 2NO + 4H2O A. Cu B. H C. N D. O E. H2O Answer: A
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What element is oxidized in the following reaction? M Cd + NiO2 + 2H2O Cd(OH)2 + Ni(OH)2 A. Cd B. Ni C. O D. H Answer: A
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What element is oxidized in the following reaction? M H2SO4 + Cd(OH)2 2H2O + CdSO4 A. H B. S C. O D. Cd E. none of these Answer: E
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What element is reduced in the following reaction? M Cu + 2H2SO4 CuSO4 + SO2 + 2H2O A. Cu B. H C. S D. O E. H2O Answer: C
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What is the molar concentration of ions in a solution prepared by mixing M 100 mL of 2.0M KCl with 50 mL of a 1.5M CaCl2 solution? Answer: 4.2 M
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What is the molarity of a solution in which 26.0 grams of BaCl2 M (molar mass = 208.2 g/mol) are dissolved in enough water to make 450.0 mL of solution? A. 0.278 M B. 0.617 M C. 1.00 M D. 3.41 M Answer: A
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What is the molarity of a solution that contains 5.0 moles of solute in 2.00 liters of E solution? Answer: 2.5 M
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What is the oxidation number of N in NaNO3? M A. +1 B. +2 C. +3 D. +4 E. +5 Answer: E
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What is the substance acting as a Bronsted-Lowry acid in the following reaction. M HSO4─ + NH4+ H2SO4 + NH3 Answer: NH4+
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What volume of 0.122 M HCl would react with 26.2 mL of 0.176 M NaOH? M A. 37.8 mL B. 18.2 mL C. 5.56 mL D. 26.3 mL E. 75.6 mL Answer: A
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What volume of concentrated nitric acid (15.0 M) is required to make 100 mL of a M 3.0 M nitric acid solution? Answer: 20 mL
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When balanced, what is the coefficient of Sn in the equation? M Sn + HNO3 SnO2 + NO2 + H2O (acidic solution) A. 1 B. 2 C. 3 D. 4 E. 5 Answer: A
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Which is the oxidation number of arsenic in K3AsO4? M A. +2 B. +3 C. +4 D. +5 E. +6 Answer: D
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Which of the following compounds are INCORRECTLY classified with respect to its solubility in water? M A. NaBr / soluble B. KCrO4 / insoluble C. MgCl2 / soluble D. AgCl / insoluble E. PbS / insoluble Answer: B
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Which of the following is INCORRECTLY classified? (Ac = acetate ion) E A. HAc / weak electrolyte B. HCl / strong electrolyte C. NaCl / strong electrolyte D. NaOH / weak electrolyte E. H2O / nonelectrolyte Answer: D
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Which of the following is a displacement reaction? E A. 2NaN3(s) 2Na(s) + 3N2(g) B. Fe2O3(s) + 2Al(s) 2Fe(s) + Al2O3(s) C. 3NO2(g) + H2O(l) 2HNO3(aq) + NO(g) D. 2P(s) + 3Cl2(g) 2PCl3(g) E. 2ZnS(s) + 3O2(g) 2ZnO(s) + 2SO2(g) Answer: B
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Which of the following is a halogen displacement reaction? E A. 2KBr(aq) + Cl2(g) 2KCl(aq) + Br2(l) B. 2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g) C. CaBr2(aq) + H2SO4(aq) CaSO4(s) + 2HBr(g) D. 2KNO3(s) 2KNO2(s) + O2(g) E. 2LiOH(aq) + H2SO4(aq) Li2SO4(aq) + 2H2O(l) Answer: A
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Which of the following is a precipitation reaction? M A. 2H2(g) + O2(g) 2H2O(l) B. CaBr2(aq) + H2SO4(aq) CaSO4(s) + 2HBr(g) C. 2KNO3(s) 2KNO2(s) + O2(g) D. 2KBr(aq) + Cl2(g) 2KCl(aq) + Br2(l) E. 2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g) Answer: B
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Which of the following is an acid-base neutralization reaction? E A. 2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g) B. SO2(g) + H2O(l) H2SO3(g) C. LiOH(aq) + HNO3(aq) LiNO3(aq) + H2O(l) D. 2KBr(aq) + Cl2(g) 2KCl(aq) + Br2(l) E. CaBr2(aq) + H2SO4(aq) CaSO4(s) + 2HBr(g) Answer: C
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Which of the following is the correct NET IONIC equation for the M neutralization of acetic acid (HAc) with Ca(OH)2? (Ac = acetate ion) A. 2 HAc + Ca(OH)2 CaAc2 + 2 H2O B. H+ + OH ─ H2O C. HAc + OH ─ Ac ─ + H2O A. 2 H+ + Ca(OH)2 Ca2+ + 2 H2O Answer: C
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Which reaction below is NOT an oxidation-reduction reaction? M A. CaCl2(aq) + Na2CO3(aq) CaCO3(s) + 2 NaCl(aq) B. 2 Na(s) + 2 H2O(l) 2 NaOH(aq) + H2(g) C. 2 H2(g) + O2(g) 2 H2O(g) D. Zn(s) + Cu(NO3)2(aq) Zn(NO3)2(aq) + Cu(s) Answer: A
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What is the molarity of a solution that contains 5.0 moles of solute in 2.00 liters of solution?
2.5 M
The specific heat of silver is 0.235 J/g•°C. How many joules of heat are required to heat a 75 g silver spoon from 20°C to 35°C?
260 J
Gasoline (which can be considered to be octane, C8H18) burns in oxygen to produce carbon dioxide and water. What volume of carbon dioxide at STP is generated as a result of the combustion of 1.0 gal of gasoline? (The density of gasoline is 0.81 g/mL. 1 gal = 3.78 L)
4800 L
What volume of H2 is formed at STP when 6.0 g of Al is treated with excess NaOH? 2NaOH + 2Al + 6H2O 2NaAl(OH)4 + 3H2(g)
7.5 L
Use the Born-Haber cycle to calculate the lattice energy of NaBr(s) given the following data: H(sublimation) Na = 109 kJ/mol I1 (Na) = 496 kJ/mol Bond energy (Br-Br) = 192 kJ/mol EA (Br) = 324 kJ/mol Hf (NaBr(s)) = -361 kJ/mol
738 kJ/mol
Give an example of a monoprotic acid, diprotic acid, and triprotic acid.
: (answers will vary) HNO3 , H2CO3 , H3PO4
1.40 g of silver nitrate is dissolved in 125 mL of water. To this solution is added 5.00 mL of 1.50 M hydrochloric acid, and a precipitate forms. Find the concentration of silver ions remaining in the solution. A. 5.7 10-3 M B. 6.34 10-2 M C. 5.77 10-2 M D. 0.121 M E. 5.9 10-3 M
A
2.0 L of gas A at 1.0 atm and 1.0 L of gas B at 1.0 atm are combined in a 3 L flask. The flask is sealed and over time they react to completely to give gas C according to the following chemical equation: 2A(g) + B(g) C(g) Assuming the temperature stays constant, what will be the pressure after the reaction goes to completion? 0.33 atm 0.50 atm 0.67 atm 0.75 atm 1.0 atm
A
35.0 mL of 0.255 M nitric acid is added to 45.0 mL of 0.328 M Mg(NO3)2. What is the concentration of nitrate ion in the final solution? A. 0.481 M B. 0.296 M C. 0.854 M D. 1.10 M E. 0.0295 M
A
A calorimeter temperature increases by 0.45°C when 30 J of energy is added to it by electrical heating. When 0.10 grams of HCl is neutralized in the same calorimeter, the temperature increased by 7.3°C. What is the ΔH of neutralization of HCl in units of kJ/mol? A. ─177 kJ/mol B. 0.486 kJ/mol C. 1.8 102 kJ/mol D. ─486 kJ/mol 177 kJ/mol
A
A gas is allowed to expand at constant temperature from a volume of 1.0 L to 10.1 L against an external pressure of 0.50 atm. If the gas absorbs 250 J of heat from the surroundings, what are the values of q, w, and ΔE? q w ΔE A. 250 J ─460 J ─210 J B. ─250 J ─460 J ─710 J C. 250 J 460 J 710 J D. ─250 J 460 J 210 J E. 250 J ─4.55 J 245 J
A
A piece of copper with a mass of 218 g has a heat capacity of 83.9 J/oC. What is the specific heat of copper? A. 0.385 J/g•oC B. 1.83 ´ 104 J/g•oC C. 2.60 J/g•oC D. 1.32 J/g•oC E. 24.5 J/g•oC
A
A small bubble rises from the bottom of a lake, where the temperature and pressure are 4°C and 3.0 atm, to the water's surface, where the temperature is 25°C and the pressure is 0.95 atm. Calculate the final volume of the bubble if its initial volume was 2.1 mL. A) 7.1 mL B) 22.4 mL C) 6.2 mL D) 0.72 mL E) 41.4 mL
A
According to the first law of thermodynamics: A) Energy is neither lost nor gained in any energy transformations. B) Perpetual motion is possible. C) Energy is conserved in quality but not in quantity. D) Energy is being created as time passes. We have more energy in the universe now than when time began.
A
An exothermic reaction causes the surroundings to warm up. become acidic. expand. decrease its temperature. release CO2.
A
An exothermic reaction causes the surroundings to: A. warm up B. become acidic C. expand D. decrease its temperature E. release CO2
A
Based on the solubility rules, which one of these compounds should be insoluble in water? A. CaCO3 B. (NH4)2CO3 C. Na2CO3 D. K2CO3 E. KNO3
A
Calculate the density, in g/L, of CO2 gas at 27°C and 0.50 atm pressure. A) 0.89 g/L B) 1.12 g/L C) 9.93 g/L D) 46.0 g/L E) 2.17 kg/L
A
Calculate the molecular mass of menthol, C10H20O. A. 156 amu B. 140 amu C. 29 amu D. 146 amu E. 136 amu
A
Consider the element with the electron configuration [Kr]5s24d105p5. This element is A. a representative element. B. a transition metal. C. an alkali metal. D. an actinide element. E. a noble gas.
A
During volcanic eruptions, hydrogen sulfide gas is given off and oxidized by air according to the following chemical equation: 2H2S(g) + 3O2(g) 2SO2(g) + 2H2O(g) Calculate the standard enthalpy change for the above reaction given: 3S(s) + 2H2O(g) 2H2S(g) + SO2(g) H° = 146.9 kJ/mol S(s) + O2(g) SO2(g) H° = -296.4 kJ/mol -1036.1 kJ/mol -742.3 kJ/mol -149.5 kJ/mol 443.3 kJ/mol 742.3 kJ/mol
A
Find the standard enthalpy of formation of ethylene, C2H4(g), given the following data: C2H4(g) + 3O2(g) 2CO2(g) + 2H2O(l) ΔHof = ─1411 kJ C(s) + O2(g) CO2(g) ΔHof = ─393.5 kJ H2(g) + 1/2O2(g) H2O(l) ΔHof = ─285.8 kJ A. 52 kJ B. 87 kJ C. 731 kJ D. 1.41 103 kJ E. 2.77 103 kJ
A
For which of these reactions is the enthalpy change equal to the third ionization energy of vanadium? A. V2+(g) V3+(g) + e- B. V3+(g) + e- V2+(g) C. V(g) V3+(g) + 3e- D. V2-(g) + e- V3-(g) E. V3+(g) V4+(g) + e-
A
Given 2Al(s) + 3/2O2(g) Al2O3(s) ΔHof = ─1670 kJ What is ΔH for the reaction? 2Al2O3(s) 4Al(s) + 3O2(g) ΔHorxn = ? A. 3340 kJ B. 1670 kJ C. ─3340 kJ D. ─1670 kJ E. ─835 kJ
A
Given that: 2 H2(g) + O2(g) 2 H2O(l); ΔH° = ─571 kJ/mol C3H4(g) + 4 O2(g) 3 CO2(g) + 2 H2O(l); ΔH° = ─1941 kJ/mol C3H8(g) + 5 O2(g) 3 CO2(g) + 4 H2O(l); ΔH° = ─2220 kJ/mol Calculate the ΔH° value for the reaction C3H4(g) + 2 H2(g) C3H8(g) A. ─292 kJ/mol B. +292 kJ/mol C. +850 kJ/mol ─850 kJ/mol
A
Glycine C2H5O2N is important for biological energy. The combustion of glycine is given by the equation, 4C2H5O2N(s) + 9O2(g) 8CO2(g) + 10H2O(l) + 2N2(g) ΔHorxn = ─3857 kJ Given that ΔHof[CO2(g)] = ─393.5 kJ/mol, and ΔHof[H2O(l)] = ─285.8 kJ/mol. Calculate the enthalpy of formation ΔHof per mole of glycine. A. ─537.2 kJ/mol B. ─268.2 kJ/mol C. 2149 kJ/mol D. ─3178 kJ/mol E. ─964 kJ/mol
A
Glycine, C2H5O2N, is important for biological energy. The combustion reaction of glycine is given by the equation 4C2H5O2N(s) + 9O2(g) 8CO2(g) + 10H2O(l) + 2N2(g) H°rxn = -3857 kJ/mol Given that H°f[CO2(g)] = -393.5 kJ/mol and H°f[H2O(l)] = -285.8 kJ/mol, calculate the enthalpy of formation of glycine. -537.2 kJ/mol -268.2 kJ/mol 2,149 kJ/mol -3,178 kJ/mol -964 kJ/mol
A
How many atoms are in 0.0728 g of PCl3? A. 1.28 1021 atoms B. 4.38 1022 atoms C. 4.39 1021 atoms D. 3.19 1020 atoms E. 6.02 1024 atoms
A
How many moles of HCl are represented by 1.0 1019 HCl molecules? A. 1.7 10-5 mol B. 1.5 10-3 mol C. 1.0 1019 mol D. 36.5 mol E. 6.02 104 mol
A
How much heat is absorbed in the complete reaction of 3.00 grams of SiO2 with excess carbon in the reaction below? ΔH° for the reaction as written is +624.7 kJ. SiO2(g) + 3C(s) SiC(s) + 2 CO(g) A. 31.2 kJ B. 1.13 105 kJ C. 5.06 kJ D. 1.33 104 kJ E. 366 kJ
A
Identify the major ionic species present in an aqueous solution of CaCO3. A. Ca2+, CO32- B. Ca2+, C2-, O3 C. Ca+, C4+, O32- D. Ca2+, C+, O2- E. Ca2+, CO32-
A
Identify the reducing agent in the following chemical reaction. 5Fe2+(aq) + MnO4-(aq) + 8H+(aq) 5Fe3+(aq) + Mn2+(aq) + 4H2O(l) Fe2+ MnO4- H+ Mn2+ Fe3+
A
Liquid heptane, C7H16, burns in oxygen gas to yield carbon dioxide and water. What mass of water is produced when 15.0 mL of heptane burns completely? [Given: density of heptane = 0.6838 g/mL] A. 14.8 g B. 2.70 g C. 31.6 g D. 1.85 g E. 21.6 g
A
Octane (C8H18) undergoes combustion according to the following thermochemical equation: 2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ. Given that: ΔHof[CO2(g)] = ─393.5 kJ/mol ΔHof[H2O(l)] = ─285.8 kJ/mol Calculate the enthalpy of formation of 1 mole of octane. A. ─210 kJ B. ─11,230 kJ C. 22,040 kJ D. ─420 kJ E. 420 kJ
A
One method of determining the concentration of hydrogen peroxide (H2O2) in a solution is through titration with iodide ion. The net ionic equation for this reaction is H2O2 + 2I- +2H+ I2 + 2H2O A 50.00 mL sample of a hydrogen peroxide solution is found to react completely with 37.12 mL of a 0.1500 M KI solution. What is the concentration of hydrogen peroxide in the sample? A. 5.568 10-2 M B. 0.2227 M C. 0.1010 M D. 0.4041 M E. 0.1114 M
A
Predict the products of the following single replacement reaction. Fe(s) + CuSO4(aq) A) Cu(s) + FeSO4(aq) B) Fe(s) + Cu(s) + SO4(aq) C) CuS(s) + Fe2SO4(aq) D) FeCuSO4(aq) E) FeO(s) + CuSO3(aq)
A
Predict the products of the single replacement reaction Fe(s) + CuSO4(aq) ? A. Cu(s) + FeSO4(aq) B. Fe(s) + Cu(s) + SO4(aq) C. CuS(s) + Fe2SO4(aq) D. FeCuSO4(aq) E. FeO(s) + CuSO3(aq)
A
The electron affinity of oxygen is equal to A. the ionization energy of O-. B. the ionization energy of O2-. C. the second ionization energy of O. D. twice the electron affinity of O+. E. none of these.
A
The formula for calcium phosphate is A) Ca3(PO4)2. B) Ca3P2. C) CaPO4. D) Ca3(PO3)2. E) Ca2(PO4)3.
A
The general electron configuration for noble gas atoms is A. ns2np6. B. ns2np5. C. ns2np4. D. ns2np3. E. ns2.
A
The oxidation number of Fe in K3Fe(CN)6 is A. +3. B. +2. C. +1. D. -3. E. -4.
A
The pressure of a gas sample was measured to be 654 mmHg. What is the pressure in kPa? (1 atm = 1.01325 105 Pa) 87.2 kPa 118 kPa 6.63 104 kPa 8.72 104 kPa 8.72 107 kPa
A
Use bond energies to estimate the enthalpy change for the reaction of one mole of CH4 with chlorine gas to give CH3Cl and hydrogen chloride. BE(C-H) = 414 kJ/mol BE(C-Cl) = 326 kJ/mol BE(H-Cl) = 432 kJ/mol BE(Cl-Cl) = 243 kJ/mol A. -101 kJ/mol b. -106 kJ/mol c. +331 kJ/mol d. +106 kJ/mol e. +101 kJ/mol
A
What element is oxidized in the chemical reaction 3Cu + 8HNO3 3Cu(NO3)2 + 2NO + 4H2O? A. Cu B. H C. N D. O E. H2O
A
What is the charge on the monatomic ion that calcium forms in its compounds? A. +2 B. +1 C. -1 D. -2 E. -3
A
When 22.0 g NaCl and 21.0 g H2SO4 are mixed and react according to the equation below, which is the limiting reagent? 2NaCl + H2SO4 Na2SO4 + 2HCl A. NaCl B. H2SO4 C. Na2SO4 D. HCl E. No reagent is limiting.
A
Which of these choices is the electron configuration of the iron(III) ion? A. [Ar]3d5 B. [Ar]4s13d5 C. [Ar]4s23d3 D. [Ar]3d6 E. [Ar]4s23d9
A
Which one of the following is a redox reaction? A) 2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g) B) 2KBr(aq) + Pb(NO3)2(aq) 2KNO3(aq) + PbBr2(s) C) CaBr2(aq) + H2SO4(aq) CaSO4(s) + 2HBr(g) D) H+(aq) + OH- (aq) H2O(l) E) CO32- (aq) + HSO4-(aq) HCO3- (aq) + SO42- (aq)
A
Which one of these elements is a transition element? A. Nickel B. Tin C. Sodium D. Sulfur E. Calcium
A
Which one of these ions is not isoelectronic with Kr? A. As3+ B. Se2- C. Rb+ D. Sr2+ E. Br-
A
Define precipitate and illustrate with an example.
A precipitate is an insoluble solid that separates from a solution. CoCl2 (aq) + Na2CO3(aq) CoCO3 (s) + 2NaCl (aq) CoCO3 would be the precipitate in this reaction.
Define solution, solute and solvent.
A solution is a homogeneous mixture of two or more substances. The substance present in a smaller amount is called the solute, while the substance present in the larger amount is called the solvent.
Define solution, solute, and solvent.
A solution is a homogeneous mixture of two or more substances. The substance present in a smaller amount is called the solute, while the substance present in the larger amount is called the solvent.
The density of mercury, the only metal to exist as a liquid at room temperature, is 13.6 g/cm3. What is that density in pounds per cubic inch? 1 inch = 2.54 cm, 1 pound = 454 grams
A. 0.491 lb/in3
Electrons can be used to probe the arrangement of atoms on a solid surface if the wavelength of the electrons is comparable with the spacing between the atoms. Which of the following electron velocities would be appropriate for use in this application if the atoms are separated by 0.320 nm? A. 2.27 106 m/s B. 1.24 103 m/s C. 3.00 108 m/s D. 4.41 106 m/s E. 8.06 103 m/s
A. 2.27 106 m/s
Calculate the frequency of visible light having a wavelength of 686 nm. A. 4.37 1014 /s B. 4.37 105 /s C. 6.17 1014 /s D. 2.29 10-15 /s E. 2.29 10-6 /s
A. 4.37 1014 /s
When the electron in a hydrogen atom falls from the n = 3 excited energy level to the ground state energy level, a photon with wavelength is emitted. An electron having this same wavelength would have a velocity of A. 7.10 103 m/s. B. 2.93 106 m/s. C. 2.93 103 m/s. D. 7.10 m/s. E. 3.00 108 m/s.
A. 7.10 103 m/s.
Calculate the wavelength of the light emitted by a hydrogen atom during a transition of its electron from the n = 4 to the n = 1 principal energy level. Recall that for hydrogen En = -2.18 10-18 J(1/n2) A. 97.2 nm B. 82.6 nm C. 365 nm D. 0.612 nm E. 6.8 10-18 nm
A. 97.2 nm
Silver chloride is used in photographic emulsions. What is its formula?
A. AgCl
Ferrocene, Fe(C5H5)2(s), can be prepared by reacting 3.0 g of FeCl2(s) with an equal mass of cyclopentadiene, C5H6(l), and an excess of KOH, as shown in the following reaction FeCl2 + 2C5H6 + 2KOH FeC10H10 + 2H2O A. What is the limiting reagent in this procedure? B. Based on your answer to part A, what mass of Fe(C5H5)2 could theoretically be formed? C. A student who carried out this reaction obtained 2.7 g of ferrocene. What was the percent yield for this reaction?
A. C5H6 is limiting B. 4.2 g of ferrocene C. 64% yield
Which one of the following combinations of names and formulas of ions is incorrect?
A. NO2- nitrate
The orbital diagram for a ground-state nitrogen atom is A. Row 1. B. Row 2. C. Row 3. D. Row 4.
A. Row 1. updown, updown, up, up, up
Which element has the following ground-state electron configuration? [Kr]5s24d105p2 A. Sn B. Sb C. Pb D. Ge E. Te
A. Sn
The ground-state electron configuration of Cr, Mo, and Ag are exceptions to the Aufbau principle. Which of the following is the electron configuration for Mo? A. [Kr]5s14d5 B. [Kr]5s24d4 C. [Xe]6s25d4 D. [Ar]4s24d4 E. [Kr]5s24d6
A. [Kr]5s14d5
Which ground-state atom has an electron configuration described by the following orbital diagram? [ne] updown/3s, up, up/3p, up, oo A. phosphorus B. nitrogen C. arsenic D. vanadium E. none of these
A. phosphorus
Rutherford bombarded gold foil with alpha () particles and found that a small percentage of the particles were deflected. Which of the following was not accounted for by the model he proposed for the structure of atoms?
A. the total mass of the atom
Identify the element being oxidized, the element being reduced, the oxidizing M agent, and the reducing agent in the following reactions. 4Al + 3O2 2Al2O3
Al is oxidized; O2 is reduced; Al is the reducing agent; O2 is the oxidizing agent
If we have 75 g of water at 25oC to boil to dryness: a. How much heat is added to the water to raise the temperature to 100oC? b. How much heat is added to evaporate the water? c. What is the total amount of heat used? Heat of fusion of water = 335 J/g Specific heat of water = 4.189 J/g•oC Heat of vaporization = 2262 J/g
Answer: a. 24 kJ b. 170 kJ c. 190 kJ
The combustion of one mole of benzene, C6H6, in oxygen liberates 3268 kJ of heat. The products of the reaction are carbon dioxide and water. a. Write the thermochemical equation for the combustion of benzene. b. Is the reaction exothermic or endothermic? c. How much heat is given off when 8 moles of benzene are burned? d. How much heat is given off when 183 gms of oxygen are reacted?
Answer: a. 2C6H6(l) + 15O2(g) 12CO2(g) + 6H2O(g) + 6536 kJ b. exothermic c. 26,140 kJ d. 2490 kJ
Ice cubes are made by taking heat away from water. If you put 500 g of 20oC water in an ice tray and put it into the freezer: a. How many joules of heat must be removed to cool the water to 0oC? b. How many joules of heat must be removed to change water from liquid to solid? c. What is the total heat removed? Heat of fusion of water = 335 J/g Specific heat of water = 4.189 J/g•oC Heat of vaporization = 2262 J/g
Answer: a. 41.9 kJ b. 168 kJ c. 209 kJ
What is the standard enthalpy of formation of H2(g) ?
Answer: 0 kJ
The heat released when one mole of water is formed from the elements is 1198 kJ. An experiment was conducted that permitted water to form in this manner, and the heat was contained in 2.0 liters of water. The water temperature before the reaction was 34.5oC, and after the reaction it had risen to 52.0oC. How many moles of water were formed? The specific heat of water is 4.184 J/g•oC
Answer: 0.12 moles
A 26.2 g piece of copper metal is heated from 21.5oC to 201.6oC. Calculate the heat absorbed by the metal. The specific heat of Cu is 0.385 J/g •oC.
Answer: 1820 J
The enthalpy of combustion of acetylene C2H2 is C2H2(g) + 5/2O2(g) 2CO2(g) + H2O(l) ΔHorxn= ─1299 kJ Calculate the enthalpy of formation of acetylene, given the following enthalpies of formation ΔHof[CO2(g)] = ─393.5 kJ/mol ΔHof[H2O(l)] = ─285.8 kJ/mol
Answer: 227 kJ
A 0.1946 g piece of magnesium metal is burned in a constant volume calorimeter that has a heat capacity of 1349 J/oC. The calorimeter contains 500 g of water and the temperature rise is 1.40oC. Calculate the heat of combustion of magnesium metal in kJ/g.
Answer: 24.8 kJ/g
The specific heat of silver is 0.235 J/g for each degree celsius change in temperature. How many joules of heat are required to heat a 75 g silver spoon from 20oC to 35oC?
Answer: 260 J
Write the net ionic equation for the following reaction. Aqueous iron (III) sulfate is E added to aqueous sodium sulfide to produce iron (III) sulfide solid and aqueous sodium sulfate.
Answer: 2Fe3+ (aq) + 3S2 ─ (aq) Fe2S3 (s)
Thunderstorms are powered by changing water vapor to rain drops. How much heat is released when a gallon of water falls? 1 gal = 1816 g
Answer: 4,108 kJ
A feverish student weighing 75 kilograms was immersed in 400 kg of water at 4.0oC to try to reduce the fever. The student's temperature dropped from 40oC to 37oC. Assuming the specific heat of the student to be 3.77 J/g•oC, what was the final temperature of the water?
Answer: 4.5oC
What is the ΔHrxn for the reaction. 2Ag2S(s) + 2H2O(l) 4Ag(s) + 2H2S(g) + O2(g) ΔHof Ag2S(s) = ─32.6 kJ; ΔHof H2S(g) = ─20.5 kJ; ΔHof H2O(l) = ─285.5 kJ
Answer: 595.2 kJ
At body temperature it requires 2404 joules to evaporate 1 g of water. After vigorous exercise a person feels chilly because their body is giving up heat to evaporate the perspiration. A typical person perspires 25 mL of water after 20 minutes of exercise. How much body heat is this person using to evaporate this water?
Answer: 60,100 J
When an automobile engine starts, the metal parts immediately begin to absorb heat released during the combustion of gasoline. How much heat will be absorbed by a 165 kg iron engine block when the temperature rises from 15.7oC to 95.7oC? The specific heat of iron is 0.489 J/g•oC.
Answer: 6450 kJ
The value of ΔHorxn for the following reaction is -6535 kJ. How many kJ of heat will be evolved during the combustion of 16.0 g of C6H6(l)? 2C6H6(l) + 15O2(g) 12CO2(g) + 6H2O(g)
Answer: 670 kJ
The heat of neutralization of HCl by NaOH is given below: HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l) ΔHorxn = ─56.2 kJ/mol How much heat is released when 125 mL of 1.750 M HCl is mixed with 195 mL of 0.667 M NaOH?
Answer: 7.31 kJ
How many grams of ethylene (C2H4) would have to be burned to produce 450 kJ of heat? C2H4 + 3O2 2CO2 + H2O ΔHorxn= ─1411 kJ
Answer: 8.95 g
According to the solubility rules, which one of the following compounds is insoluble E in water? A. CaCO3 B. (NH4)2CO3 C. Na2CO3 D. K2CO3 E. KNO3
Answer: A
According to the solubility rules, which one of the following is soluble in water? E A. (NH4)3PO4 B. Ca3(PO4)2 C. AlPO4 D. Ag3PO4 E. Mg3(PO4)2
Answer: A
The oxidation number of Fe in K3Fe(CN)6 is: H A. +3 B. +2 C. +1 D. ─ 3 E. ─ 4
Answer: A
The oxidation number of S in K2SO4 is: M A. +6 B. +4 C. +2 D. ─ 1 E. none of these
Answer: A
Define exothermic process
Answer: Any process that gives off heat to the surroundings.
Define endothermic process.
Answer: Any process that takes in heat from the surroundings.
According to the solubility rules, which one of the following compounds is insoluble E in water? A. Na2SO4 B. BaSO4 C. CuSO4 D. MgSO4 E. Rb2SO4
Answer: B
According to the solubility rules, which one of the following is soluble in water? E A. Hg2Cl2 B. Na2S C. Ag2CO3 D. Ag2S E. BaSO4
Answer: B
Identify the ions present in an aqueous solution of LiOH. E A. Li2+, O─ , H─ B. Li+, OH─ C. LiO─, H+ D. Li+, O2 ─ , H+ E. Li ─ , OH+
Answer: B
In the following reaction the oxidizing agent is: H 5H2O2 + 2MnO4─ + 6H+ 2Mn2+ + 8H2O + 5O2 A. H2O2 B. MnO4─ C. H+ D. Mn2+ E. O2
Answer: B
The common constituent in all acid solutions is: M A. H2 B. H+ C. OH─ D. H2SO4 E. Cl─
Answer: B
The distinguishing characteristic of all electrolyte solutions is that they: E A. contain molecules B. conduct electricity C. react with other solutions D. always contain acids E. conduct heat
Answer: B
The maximum oxidation number of nitrogen is: H A. +8 B. +5 C. +3 D. +1 E. ─ 3
Answer: B
The oxidation number of Mn in KMnO4 is: M A. +8 B. +7 C. +5 D. ─ 7 E. ─ 8
Answer: B
The oxidation number of N in NaNO3 is: M A. +6 B. +5 C. +3 D. ─ 3 E. none of these
Answer: B
What choice gives the correct formula of the salt formed in the neutralization E reaction of hydrochloric acid and calcium hydroxide? A. CaO B. CaCl2 C. CaH2 D. CaCl E. CaClH
Answer: B
Which of the following compounds is a weak electrolyte? E A. HCl B. CH3COOH (acetic acid) C. C6H12O6 (glucose) D. O2 E. NaCl
Answer: B
Which of the following compounds is a weak electrolyte? E A. HCl B. NH3 C. C6H12O6 (glucose) D. N2 E. KCl
Answer: B
Which of the following is the correct net ionic equation for the reaction that occurs M when solutions of Pb(NO3)2 and NH4Cl are mixed? A. Pb(NO3)2(aq) + 2NH4Cl(aq) NH4NO3(aq) + PbCl2(s) B. Pb2+(aq) + 2Cl─(aq) PbCl2(s) C. Pb2+(aq) + 2NO3─(aq) + 2NH4+(aq) + 2Cl─(aq) 2NH4+(aq) + 2NO3─(aq) + PbCl2(s) D. NH4+(aq) + NO3─(aq) 2NH4NO3
Answer: B
What is the oxidation number for each of the elements in the following compound? M BaNaPO4
Answer: Ba, +2; Na, +1; P, +5; O, -2
In accordance with the solubility rules, which of the following will occur when M solutions of CuSO4(aq) and BaCl2(aq) are mixed? A. CuCl2 will precipitate; Ba2+ and SO42 ─ will be spectator ions. B. CuSO4 will precipitate; Ba2+ and Cl ─ will be spectator ions. C. BaSO4 will precipitate; Cu2+ and Cl─ will be spectator ions. D. BaCl2 will precipitate; Cu2+ and SO42 ─ will be spectator ions. E. No precipitate will form.
Answer: C
In the following reaction the oxidizing agent is: H 5S + 6KNO3 + 2CaCO3 3K2SO4 + 2CaSO4 + CO2 + 3N2 A. S B. N2 C. KNO3 D. CaSO4 E. CaCO3
Answer: C
Select the compound below in which sulfur has its highest possible oxidation number. H A. H2S B. SO2 C. Na2SO4 D. H2SO3 E. SCl2
Answer: C
The highest possible oxidation number of carbon is: M A. +8 B. +6 C. +4 D. +2 E. ─ 4
Answer: C
The oxidation number of Cl in ClO3─ is: H A. ─ 1 B. +7 C. +5 D. +3 E. none of these
Answer: C
What is the chemical formula of the salt produced by neutralization of potassium M hydroxide (KOH) with sulfuric acid (H2SO4)? A. KSO3 B. K2(SO4)3 C. K2SO4 D. K(SO4)2 E. KSO4
Answer: C
Which of the following compounds is a strong electrolyte? E A. H2O B. N2 C. KOH D. C2H6O (ethanol) E. CH3COOH (acetic acid)
Answer: C
Which of the following compounds is a strong electrolyte? E A. H2O B. O2 C. H2SO4 D. C6H12O6 (glucose) E. CH3COOH (acetic acid)
Answer: C
Which of the following reactions does not represent an oxidation- M reduction reaction? A. 3Al + 6HCl 3H2 + AlCl3 B. 2H2O 2H2 + O2 C. 2NaCl + Pb(NO3)2 PbCl2 + 3NaNO3 D. 2NaI + Br2 2NaBr + I2
Answer: C
What is the oxidation number for each of the elements in the following compound? M Cs2Cr2O7
Answer: Cs1+, Cr6+, O2 ─
According to the solubility rules, which one of the following compounds is insoluble E in water? A. NaCl B. MgBr2 C. FeCl2 D. AgBr E. ZnCl2
Answer: D
According to the solubility rules, which one of the following is soluble in water? E A. AgBr B. AgCl C. Ag2CO3 D. AgNO3 E. Ag2S
Answer: D
According to the solubility rules, which one of the following is soluble in water? E A. CaSO4 B. BaSO4 C. PbSO4 D. K2SO4
Answer: D
In accordance with the solubility rules, which of the following will occur when M solutions containing about 0.1 g of Pb(NO3)2(aq) and KI(aq) /100 mL are mixed? A. KNO3 will precipitate; Pb2+ and I─ will be spectator ions. B. No precipitate will form. C. Pb(NO3)2 will precipitate; K+ and I─ will be spectator ions. D. PbI2 will precipitate; K+ and NO3─ will be spectator ions. E. Pb2+ and I─ will be spectator ions, and PbI2 will precipitate.
Answer: D
The oxidation number of Cr in Cr2O72 ─ is: H A. ─ 12 B. ─ 7 C. ─ 2 D. +6 E. +7
Answer: D
What is the chemical formula of the salt produced by neutralization of sodium M hydroxide with sulfuric acid? A. NaSO3 B. Na2(SO4)3 C. Na(SO4)2 D. Na2SO4 E. Na3SO4
Answer: D
Which choice below gives the oxidation numbers for all three elements in Rb2SO3 M correctly, and in the order shown in the formula? A. ─ 2, +6, ─ 2 B. ─ 1, +4, ─ 3 C. +2, +4, ─ 2 D. +1, +4, ─ 2 E. +1, +6, ─ 6
Answer: D
Which one of the following is a redox reaction? M A. H+(aq) + OH ─ (aq) H2O(l) B. 2KBr(aq) + Pb(NO3)2(aq) 2KNO3(aq) + PbBr2(s) C. CaBr2(aq) + H2SO4(aq) CaSO4(s) + 2HBr(g) D. 2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g) E. CO32 ─ + HSO4─ HCO3─ + SO42 ─
Answer: D
Identify the major ionic species present in an aqueous solution of Ca(OH)2. E A. Ca2+, H+, O2 ─ B. Ca2+, OH2─ C. Ca+, H─, O2 ─ D. Ca2+, O2H22 ─ E. Ca2+, OH ─
Answer: E
Identify the major ionic species present in an aqueous solution of NaNO3. M A. Na2+, NO3 ─ B. Na+, N3 ─ , O3 C. Na+, N3 ─, O32 ─ D. Na+, N+, O2 ─ E. Na+, NO3 ─
Answer: E
Identify the major ions present in an aqueous solution of HNO3. E A. HN+, O2 ─ B. OH─ , NO3─ C. OH─ , NO+ D. H+, N3─, O2 ─ E. H+, NO3─
Answer: E
In accordance with the solubility rules, which of the following will occur when M solutions of ZnSO4(aq) and MgCl2(aq) are mixed? A. ZnCl2 will precipitate; Mg2+ and SO42 ─ will be spectator ions. B. ZnSO4 will precipitate; Mg2+ and Cl─ will be spectator ions. C. MgSO4 will precipitate; Zn2+ and Cl─ will be spectator ions. D. MgCl2 will precipitate; Zn2+ and SO42 ─ will be spectator ions. E. No precipitate will form.
Answer: E
What is the chemical formula of the salt produced by neutralization of E hydrobromic acid with Mg(OH)2? A. MgBr B. Mg2Br3 C. Mg3Br2 D. Mg2Br E. MgBr2
Answer: E
What is the chemical formula of the salt produced by neutralization of nitric acid M with Ca(OH)2? A. CaNO3 B. Ca2(NO3)3 C. Ca3(NO3)2 D. Ca2NO3 E. Ca(NO3)2
Answer: E
Which of the following compounds is a nonelectrolyte? E A. NaF B. HNO3 C. CH3COOH (acetic acid) D. NaOH E. C6H12O6 (glucose)
Answer: E
Which of the following compounds is a nonelectrolyte? E A. NaOH B. HNO3 C. CH3COOH (acetic acid) D. KF E. C2H6O (ethanol)
Answer: E
What is the oxidation number for each of the elements in the following compound? M K2TaF7
Answer: K, +1; Ta, +5; F, -1
Measuring Heat of Reaction for a simple system An important thermodynamic property in a reaction is the molar enthalpy of reaction (qsys). The molar enthalpy of reaction is defined as the heat absorbed by the system from the surroundings in a reaction when one mole of product is formed. If the reaction is carried out in aqueous solution, the heat liberated or absorbed by the system can be calculated by measuring the temperature change of the surroundings - the water - by using the formula: qw = (mass)w (Specific Heat)w (Δt)w The heat change of the system (qsys) will be the same value but opposite in sign. This value is the amount of heat actually liberated in the experiment, it is not the molar heat of reaction! (qsys) To find the molar heat of reaction, the quantity of one of the products must be found. (Not the total moles of the product, just the moles of one of the product; e.g. the moles of water formed.) The molar heat of reaction then would be the heat released during the experiment divided by the moles of water formed. Working in a general chemistry lab, you perform the following experiment: Measure the initial temperature of each of the following solutions as accurately as possible. Record these temperatures. Pour exactly 50 mL of the 2.0 M NaOH into a clean, dry, styrofoam cup. Add exactly 50 mL of the 2.0 M HCl and stir gently with a thermometer. Record the highest reading observed on the thermometer. Since the solutions are diluted, or mostly water, the total amount of water present in the cup will be assumed to be exactly 100 mL. Specific heat of water = 4.184 J/g•oC You obtain the following data. a. Initial temperature of NaOH: 20oC b. Initial temperature of HCl: 20oC c. Final temperature of NaOH + HCl: 33oC d. Total volume of water in the reaction vessel: 100 mL Answer the following questions (show your work) a. Temperature change (ΔT) in reaction 1 ? b. Heat absorbed by the water in reaction 1 ? c. How much heat was liberated in the reaction ? d. How many moles of product were formed in the reaction? (stoichiometry) e. How much heat was liberated per mole of product? (ΔHorxn)
Answer: a. 13oC, b. 5446 J, c. 5446 J, d. 0.1 mole, e. 54,460 J/mol
A 0.3423 g sample of pentane, C5H12, was burned in a bomb calorimeter. The temperature of the calorimeter and the 1 kg of water rose from 20.22oC to 22.82oC. The heat capacity of the calorimeter is 2.21 kJ/oC. a. How much heat was given off during combustion of the sample of pentane? b. What is the heat of combustion per gram of pentane? c. What is the heat of combustion per mole of pentane?
Answer: a. 16.6 kJ b. 48.6 kJ c. 3.50 MJ
Calculate the enthalpy of reaction for H2(g) + C2H4(g) C2H6(g) ΔHorxn = ? Given the following standard enthalpies of formation at 25oC. ΔHof[C2H4(g)] = 52.3 kJ/mol ΔHof[C2H6(g)] = ─84.7 kJ/mol
Answer: ─137 kJ
What would be the standard enthalpy change for the reaction of one mole of H2(g) with one mole of Cl2(g) to produce two moles of HCl(g) at standard at standard state conditions? ΔHof = ─92.3 kJ; H2(g) + Cl2(g) 2HCl(g)
Answer: ─184.6 kJ
What is the ΔHrxn for the reaction. 2Na(s) + 2H2O(l) 2NaOH(s) + 2H2(g) ΔHof NaOH(s) = ─426.8 kJ; ΔHof H2O(l) = ─285.5 kJ
Answer: ─282.6 kJ
What is the ΔHorxn for the reaction. CH4(g) + 2O2(g) CO2(g) + 2H2O(l) ΔHof CH4(g) = ─74.8 kJ; ΔHof CO2(g) = ─393.5 kJ; ΔHof H2O(l) = ─285.5 kJ
Answer: ─889.7 kJ
Given the following ΔH values H2(g) + 1/2O2(g) H2O(l) ΔHof = ─285.8 kJ H2O2(l) H2(g) + O2(g) ΔHrxn = 187.6 kJ Calculate ΔHrxn for the following reaction H2O2(l) H2O(l) + 1/2O2(g)
Answer: ─98.2 kJ
0.820 mole of hydrogen gas has a volume of 2.00 L at a certain temperature and pressure. What is the volume of 0.125 mol of this gas at the same temperature and pressure? A) 4.01 L B) 0.305 L C) 0.0512 L D) 19.5 L E) 0.250 L
B
10.1 g CaO is dropped into a styrofoam coffee cup containing 157 g H2O at 18.0oC. If the following reaction occurs, then what temperature will the water reach assuming that the cup is a perfect insulator and that the cup absorbs only a negligible amount of heat? CaO(s) + H2O(l) Ca(OH)2(s) ΔHorxn = ─64.8 kJ/mol A. 18.02oC B. 35.8oC C. 311oC D. 42.2oC E. 117oC
B
A 0.9182 g sample of CaBr2 is dissolved in enough water to give 500. mL of solution. What is the calcium ion concentration in this solution? A) 4.59 103 M B) 9.19 103 M C) 2.30 103 M D) 1.25 103 M E) 2.72 103 M
B
A 20.00 mL sample of 0.1015 M nitric acid is introduced into a flask, and water is added until the volume of the solution reaches 250. mL. What is the concentration of nitric acid in the final solution? A. 1.27 M B. 8.12 10-3 M C. 0.406 M D. 3.25 10-2 M E. 5.08 10-4 M
B
A 325-mL sample of solution contains 25.3 g of CaCl2. Calculate the molar concentration of Cl- in this solution. A) 0.335 M B) 1.40 M C) 1.03 M D) 0.701 M
B
A compound was discovered whose composition by mass is 85.6% C and 14.4% H. Which of the following could be the molecular formula of this compound? CH4 C2H4 C3H4 C2H6 C3H8
B
An atom of bromine has a mass about four times greater than that of an atom of neon. How many grams of neon will contain the same number of atoms as 1,000 g of bromine? A. 4 g Ne B. 250 g Ne C. 400 g Ne D. 1,000 g Ne E. 4,000 g Ne
B
An average home in Colorado requires 20 GJ of heat per month. How many grams of natural gas as methane must be burned to supply this energy? CH4(g) + 2O2(g) CO2(g) + 2H2O(l) ΔHorxn= ─890.4 kJ A. 1.4 103 g B. 3.6 105 g C. 7.1 10-4 g D. 2.2 104 g E. 1.4 104 g
B
Calcium nitrate tetrahydrate dissolves in cold water to the extent of 266 g per 100. cm3. What is the concentration of nitrate ions in this solution? A. 32.4 M B. 22.5 M C. 11.3 M D. 16.2 M E. 8.10 M
B
Calcium oxide and water react in an exothermic reaction. CaO(s) + H2O(l) Ca(OH)2(s) ΔHorxn = ─64.8 kJ/mol How much heat would be liberated when 7.15 g CaO(s) is dropped into a beaker containing 152 g H2O. A. 1.97 kJ B. 8.26 kJ C. 508 kJ D. 547 kJ E. 555 kJ
B
Calculate the enthalpy change for the reaction: C(graph) + 2H2(g) + 1/2O2(g) CH3OH(l) Using the following information: C(graph) + O2 CO2(g) ΔHof = ─393.5 kJ. H2(g) + 1/2O2 H2O(l) ΔHof = ─285.8 kJ. CH3OH(l) + 3/2O2(g) CO2(g) + 2H2O(l) ΔHorxn = ─726.4 kJ A. ─1691.5 kJ B. ─238.7 kJ C. 1691.5 kJ D. 47.1 kJ E. ─47.1 kJ
B
Calculate the enthalpy change for the reaction: 2C8H18(l) + 21O2(g) 8CO(g) + 8CO2(g) + 18H2O(l) ΔHorxn = ? Given: 2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ. 2CO(g) + O2(g) 2CO2(g) ΔHof = ─566.0 kJ. A. 1.0454 104 kJ B. ─8756 kJ C. 1.1586 104 kJ D. ─6,492 kJ E. ─1.0454 104 kJ
B
Calculate the volume occupied by 35.2 g of methane gas (CH4) at 25°C and 1.0 atm. R = 0.08206 Latm/Kmol. 49.2 L 53.7 L 0.0186 L 4.5 L 11.2 L
B
Calculate the work done in joules when 2.5 mol of H2O vaporizes at 1.0 atm and 25oC. Assume the volume of liquid H2O is negligible compared to that of vapor. Given 1 L•atm = 101.3 J. A. 6190 kJ B. 6.19 kJ C. 61.1 J D. 5.66 kJ E. 518 J
B
Calculate the ΔH° of the following reaction: C2H4(g) + H2(g) C2H6(l) Given the standard enthalpies of formation of the following species: Substance ΔH°f --------------------------------- C2H4(g) +52.3 kJ C2H6(l) ─84.86kJ A. +137.2 kJ B. ─137.2 kJ C. +32.6 kJ ─32.6 kJ
B
Determine the number of moles of aluminum in 96.7 g of Al. A. 0.279 mol B. 3.58 mol C. 7.43 mol D. 4.21 mol E. 6.02 1023 mol
B
Ethanol fuel (C2H5OH) burns according to the equation below. How much heat is released when 35.0 g of ethanol is burned? C2H5OH(l) + 3O2(g) 2CO2(g) + 3H2O(l) ΔHorxn = ─1367 kJ A. ─1797 kJ B. ─1040 kJ C. ─9.61 kJ D. ─4.78 104 kJ E. ─1367 kJ
B
Given the standard heats of formation for the following compounds, calculate the ΔH° heat of reaction, for the following reaction: Fe3O4(s) + CO(g) 3 FeO(s) + CO2(g) ΔHf° for Fe3O4 = ─1118 kJ ΔHf° for CO = ─110.5 kJ ΔHf° for FeO = ─272 kJ ΔHf° for CO2 = ─393.5 kJ A. 54 kJ B. 19 kJ C. ─263 kJ D. ─50 kJ 109 kJ
B
Given the thermochemical equation: 2SO2(g) + O2(g) 2SO3(g) ΔHorxn= ─198 kJ How much heat is evolved when 600 g of SO2 is burned? A. 5.46 10 ─ 2 kJ B. 928 kJ C. 1.85 103 kJ D. 59,400 kJ E. 3.71 103 kJ
B
How many grams of Cr can be produced by the reaction of 44.1 g of Cr2O3 with 35.0 g of Al according to the following chemical equation? 2Al + Cr2O3 Al2O3 + 2Cr A. 7.56 g B. 30.2 g C. 67.4 g D. 104 g E. 60.4 g
B
How many grams of nitrogen are there in 7.5 g of Ca(NO3)2? A. 0.64 g B. 1.3 g C. 0.15 g D. 1.15 g E. 2.3 g
B
How many molecules of N2 gas can be present in a 2.5 L flask at 50°C and 650 mmHg? 2.1 10-23 molecules 4.9 1022 molecules 3.1 1023 molecules 3.6 1025 molecules 0.081 molecules
B
How many moles of NH3 are there in 77.5 g of NH3? A. 0.220 mol B. 4.55 mol C. 14.0 mol D. 1.31 103 mol E. none of these
B
How many valence electrons does a tin (Sn) atom have? A. 2 B. 4 C. 14 D. 36 E. 50
B
How much heat is absorbed from the surroundings when 15 g of O2 react according to the equation? O + O2 O3 ΔHorxn= 103 kJ A. 4.6 kJ B. 48 kJ C. 96 kJ D. 32 kJ E. 110 kJ
B
How much heat is required to raise the temperature of 1500 g of water from 25oC to 52oC? A. 1500 kJ B. 169 kJ C. 6.27 kJ D. 40.5 J E. 40.5 kJ
B
Hydrochloric acid can be prepared by the following reaction: 2NaCl(s) + H2SO4(aq) 2HCl(g) + Na2SO4(s) How many grams of HCl can be prepared from 2.00 mol H2SO4 and 150 g NaCl? A. 7.30 g B. 93.5 g C. 146 g D. 150 g E. 196 g
B
In the following redox reaction 4NH3 + 3Ca(ClO)2 2N2 + 6H2O + 3CaCl2 which element is oxidized and which is reduced? H is oxidized and N is reduced N is oxidized and Cl is reduced N is oxidized and O is reduced Cl is oxidized and O is reduced Cl is oxidized and N is reduced
B
Methanol fuel (CH3OH) burns according to the equation below. How much heat is given off when 75.0 g of H methanol is burned? 2CH3OH(l) + 3O2(g) 2CO2(g) + 4H2O(l) ΔHorxn = ─1454 kJ A. 727 kJ B. 1.70 103 kJ C. 1.45 103 kJ D. 3.22 10 ─ 3 kJ E. 3.41 103 kJ
B
Pentaborane B5H9(s) burns vigorously in O2 to give B2O3(s) and H2O(l). Write and balance the combustion equation. Calculate the ΔHorxn for the combustion of 1 mol of B5H9 given the following enthalpies of formation. ΔHof[B2O3(s)] = ─1273.5 kJ/mol ΔHof[B5H9(s)] = 73.2 kJ/mol ΔHof[H2O(l)] = ─285.8 kJ/mol A. ─1.2735 MJ B. ─4.543 MJ C. ─18.170 MJ D. ─9.086 MJ E. ─8.448 MJ
B
Solid sodium hydrogen carbonate (also known as sodium bicarbonate) can be decomposed to form solid sodium carbonate, gaseous carbon dioxide, and water vapor. When the balanced chemical reaction for this process is written such that the coefficient of water is 1, what is the coefficient of carbon dioxide? A. 0 B. 1 C. 2 D. ½ E. cannot be determined
B
The combustion of butane produces heat according to the equation: 2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(l) ΔHorxn= ─5314 kJ How many grams of butane must be burned to release 6375 kJ of heat? A. 1.20 g B. 139 g C. 0.0413 g D. 69.7 g E. 97.8 g
B
The combustion of butane produces heat according to the equation: 2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(l) ΔHorxn = ─5,314 kJ What is the heat of combustion per gram of butane? A. -32.5 kJ B. -45.7 kJ C. -91.5 kJ D. -2,656 kJ E. -15,440 kJ
B
The correct name for CuSO4•5H2O is A) copper(II) sulfate acid. B) copper(II) sulfate pentahydrate. C) copper sulfate pentahydrate. D) copper(V) sulfate hydrate. E) copper sulfate acid.
B
The correct name for NH4NO3 is hydrogen nitrogen oxide. ammonium nitrate. ammonium nitrogen trioxide. hydrogen nitrate. ammonia nitrogen oxide.
B
The elements in Group 7A are known by what name? A. transition metals B. halogens C. alkali metals D. alkaline earth metals E. noble gases
B
The highest possible oxidation number of nitrogen is A. +8. B. +5. C. +3. D. +1. E. -3.
B
The molecules of different samples of an ideal gas have the same average kinetic energies, at the same pressure. temperature. volume. density.
B
Thermal energy is the energy stored within the structural units of chemical substances. the energy associated with the random motion of atoms and molecules. solar energy, i.e. energy that comes from the sun. energy available by virtue of an object's position.
B
To which one of the following reactions occurring at 25°C does the symbol H°f[HNO3(l)] refer? A) H(g) + N(g) + O3(g) HNO3(l) B) (1/2)H2(g) + (1/2)N2(g) + (3/2)O2(g) HNO3(l) C) HNO3(l) (1/2)H2(g) + (1/2)N2(g) + (3/2)O2(g) D) HNO3(l) H(g) + N(g) + 3O(g) E) H2(g) + N2(g) + O3(g) HNO3(l)
B
Use bond energies to estimate the enthalpy of formation of HBr(g). BE(H-H) = 436 kJ/mol BE(Br-Br) = 192 kJ/mol BE(H-Br) = 366 kJ/mol a. +262 kJ/mol B. -52 kJ/mol c. -104 kJ/mol d. +104 kJ/mol e. +52 kJ/mol \
B
Use the Born-Haber cycle to calculate the lattice energy of NaBr (s) given the following data: H(sublimation) Na = 177.8 kJ/mol I1 (Na) = 495.9 kJ/mol Bond energy (Br-Br) = 192.5 kJ/mol EA (Br) = 325 kJ/mol Hf (NaBr(s)) = -361.1 kJ/mol a. 1456 kJ/mol B. 806 kJ/mol c. 450 kJ/mol d. 902 kJ/mol e. 421 kJ/mol
B
Use the bond enthalpy data given to estimate the heat released when 50.0 g of propane gas, C3H8, burns in excess oxygen to yield carbon dioxide and water vapor at 25C. BE(C-C) = 347 kJ/mol BE(C=O in CO2) = 799 kJ/mol BE(C-H) = 414 kJ/mol BE(O-H) = 460 kJ/mol BE(O=O) = 498.7 kJ/mol a. 1360 kJ B. 2240 kJ c. 2370 kJ d. 1540 kJ e. 1970 kJ
B
What element is oxidized in the following chemical reaction? H2SO4 + Cd(OH)2 2H2O + CdSO4 A) O B) this is not a redox reaction C) Cd D) S E) H
B
What is the correct formula of the salt formed in the neutralization reaction of hydrochloric acid with calcium hydroxide? A. CaO B. CaCl2 C. CaH2 D. CaCl E. CaClH
B
What is the theoretical yield of chromium that can be produced by the reaction of 40.0 g of Cr2O3 with 8.00 g of aluminum according to the chemical equation below? 2Al + Cr2O3 Al2O3 + 2Cr A. 7.7 g B. 15.4 g C. 27.3 g D. 30.8 g E. 49.9 g
B
What is the theoretical yield of vanadium, in moles, that can be produced by the reaction of 1.0 mole of V2O5 with 4.0 mole of calcium based on the following chemical equation? V2O5(s) + 5Ca(l) 2V(l) + 5CaO(s) A. 1.0 mol B. 1.6 mol C. 2.0 mol D. 0.80 mol E. 3.2 mol
B
When 50.0 mL of a 0.3000 M AgNO3 solution is added to 50.0 mL of a solution of MgCl2, an AgCl precipitate forms immediately. The precipitate is then filtered from the solution, dried, and weighed. If the recovered AgCl is found to have a mass of 0.1183 g, what was the concentration of magnesium ions in the original MgCl2 solution? A. 0.300 M B. 8.25 10-3 M C. 1.65 10-2 M D. 2.06 10-5 M E. 4.13 10-3 M
B
When octane (C8H18) is burned in a particular internal combustion engine, the yield of products (carbon dioxide and water) is 93%. What mass of carbon dioxide will be produced in this engine when 15.0 g of octane is burned with 15.0 g of oxygen gas? A. 13. g B. 12. g C. 21 g D. 54. g E. 43. g
B
Which of the elements listed below has the greatest atomic radius? A. B B. Al C. S D. P E. Si
B
Which of the following compounds is a weak electrolyte? HCl NH3 C6H12O6 (glucose) N2 KCl
B
Which of the following reactions is a precipitation reaction? A) 2Li + H2 2LiH B) Ba(NO3)2 + Na2SO4 2NaNO3 + BaSO4 C) CuO + H2 Cu + H2O D) Ca + F2 CaF2
B
Which of these chemical equations describes a precipitation reaction? A. 2H2(g) + O2(g) 2H2O(l) B. CaBr2(aq) + H2SO4(aq) CaSO4(s) + 2HBr(g) C. 2KNO3(s) 2KNO2(s) + O2(g) D. 2KBr(aq) + Cl2(g) 2KCl(aq) + Br2(l) E. 2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g)
B
Which of these choices is the correct net ionic equation for the reaction that occurs when solutions of Pb(NO3)2 and NH4Cl are mixed? A. Pb(NO3)2(aq) + 2NH4Cl(aq) NH4NO3(aq) + PbCl2(s) B. Pb2+(aq) + 2Cl-(aq) PbCl2(s) C. D. NH4+(aq)+ NO3- (aq) 2NH4NO3(s) E. No reaction occurs when the solutions are mixed.
B
Which of these elements exhibits chemical behavior similar to that of silver? A. nickel B. gold C. sulfur D. chlorine E. iron F. beryllium
B
Which of these elements has the following pattern for its first six ionization energies? (I1 = first ionization energy, I2 = second ionization energy, etc.) A. Ca B. Si C. Al D. Se E. P
B
Which of these elements has the greatest electron affinity (largest positive value)? A. K B. Br C. As D. Ar E. I
B
Which of these ground-state ions has the largest number of unpaired electrons? A. Cr2+ B. Mn2+ C. Ni2+ D. Cu+ E. Co2+
B
Which one of the following reactions occurring at 25oC does the symbol ΔHof[HNO3(l)] refer to? A. H(g) + N(g) + O3(g) HNO3(l) B. 1/2H2(g) + 1/2N2(g) + 3/2O2(g) HNO3(l) C. HNO3(l) 1/2H2(g) + 1/2N2(g) + 3/2O2(g) D. HNO3(l) H(g) + N(g) + 3O(g) E. H2(g) + N2(g) + O3(g) HNO3(l)
B
What is the maximum number of electrons in a atom that can have the following set of quantum numbers? n = 4 l = 3 ml = -2 ms = +1/2 A. 0 B. 1 C. 2 D. 6 E. 10
B. 1
How many electrons in a ground-state cadmium atom are in orbitals labeled by ml = -1? A. 2 B. 10 C. 12 D. 18 E. 36
B. 10
The mass of a sample is 550 milligrams. Which of the following expresses that mass in kilograms?
B. 5.5 10-4 kg
Which one of the following statements about atoms and subatomic particles is correct?
B. A neutral atom contains equal numbers of protons and electrons.
Which of these atoms is paramagnetic both in its ground state and in all of its excited states? A. C B. N C. O D. Ti E. Cr
B. N
Identify the element being oxidized, the element being reduced, the oxidizing M agent, and the reducing agent in the following reactions. 2KBr + F2 Br2 + 2KF
Br ─ is oxidized, F2 is reduced, KBr is the reducing agent, F2 is the oxidizing agent
A 4.691 g sample of MgCl2 is dissolved in enough water to give 750. mL of solution. What is the magnesium ion concentration in this solution? 3.70 10-2 M 1.05 10-2 M 6.57 10-2 M 4.93 10-2 M 0.131 M
C
A gas is compressed in a cylinder by a constant pressure of 10 atm from a volume H of 20 L to 2.0 L. Calculate the work done on the system. A. 1.01 104 J B. -180 J C. 1.81 104 J D. ─1.81 104 J E. 180 J
C
A glass containing 200 g of H2O at 20oC was placed into a refrigerator. The water loses 11.7 kJ as it cools to a constant temperature. What is its new temperature? A. 0.013oC B. 4oC C. 6oC D. 14oC E. 34oC
C
According to the first law of thermodynamics: A. Energy is neither lost nor gained in any energy transformations. B. Perpetual motion is possible. C. Energy in a closed system is conserved. D. Energy is being created as time passes. We have more energy in the universe now than when time began.
C
Based on the solubility rules, which of the following will occur if solutions of CuSO4(aq) and BaCl2(aq) are mixed? CuCl2 will precipitate; Ba2+ and SO42- are spectator ions. CuSO4 will precipitate; Ba2+ and Cl- are spectator ions. BaSO4 will precipitate; Cu2+ and Cl- are spectator ions. BaCl2 will precipitate; Cu2+ and SO42- are spectator ions. No precipitate will form.
C
Calculate the mass of 3.00 moles of CF2Cl2. A. 3.00 g B. 174 g C. 363 g D. 1.81 1024 g E. 40.3 g
C
Calculate the volume occupied by 25.2 g of CO2 at 0.84 atm and 25°C. R = 0.08206 Latm/Kmol. 0.060 L 1.34 L 16.9 L 24.2 L 734 L
C
Consider the following reaction 2A + 3F2 2AF3. What is the formula for the reaction product if we substitute iodine for fluorine? A. A2I3 B. A3I2 C. AI3 D. A3I E. AI
C
Ethanol undergoes combustion according to the equation: C2H5OH(l) + O2(g) CO2(g) + H2O(l) (Not Balanced) The standard heat of combustion of ethanol, C2H5OH(l), is ─1366.8 kJ/mol. Given that: ΔHof[CO2(g)] = ─393.5 kJ/mol ΔHof[H2O(l)] = ─285.8 kJ/mol What is the standard enthalpy of formation of ethanol? A. 3010 kJ B. ─687.6 kJ C. ─277.6 kJ D. 687.6 kJ E. 1367 kJ
C
Given the following information: CaO(s) + H2O(l) Ca(OH)2(s) ΔHorxn = ─64.8 kJ/mol How many grams of CaO must react in order to liberate 525 kJ of heat? A. 6.92 g B. 56.1 g C. 455 g D. 606 g E. 3.40 104 g
C
Given the thermochemical equation: 2SO2 + O2 2SO3 ΔHorxn = ─198 kJ. What is the enthalpy change (ΔHo) for the decomposition of one mole of SO3? A. 198 kJ B. ─99 kJ C. 99 kJ D. 396 kJ E. ─198 kJ
C
How many grams of Cl2 can be prepared from the reaction of 16.0 g of MnO2 and 30.0 g of HCl according to the following chemical equation? MnO2 + 4HCl MnCl2 + Cl2 + 2H2O A. 0.82 g B. 5.8 g C. 13.0 g D. 14.6 g E. 58.4 g
C
How much heat is given off to the surroundings when 9.0 g of aluminum react according to the equation? 2Al + Fe2O3 Al2O3 + 2Fe ΔHorxn= ─849 kJ A. 7.6 103 kJ B. 2.8 102 kJ C. 1.4 102 kJ D. 5.6 102 kJ E. 2.5 103 kJ
C
In the chemical reaction 5S + 6KNO3 + 2CaCO3 3K2SO4 + 2CaSO4 + CO2 + 3N2, the oxidizing agent is A. S. B. N2. C. KNO3. D. CaSO4. E. CaCO3.
C
Liquid hexane, C6H14, burns in oxygen gas to yield carbon dioxide and water. What is the minimum mass of oxygen required for the complete reaction of 10.0 mL of hexane? [Given: density of hexane = 0.660 g/mL] A. 3.71 g B. 2.45 g C. 23.3 g D. 46.6 g E. 35.3 g
C
Naphthalene combustion can be used to determine the heat capacity of a bomb calorimeter. The heat of combustion of naphthalene is 40.1 kJ/g. When 0.8210 g of naphthalene was combusted in a calorimeter containing 1000 g of water a temperature rise of 4.21oC was observed. What is the heat capacity of the bomb calorimeter excluding the water? A. 32.9 kJ/oC B. 7.8 kJ/oC C. 1.76 kJ/oC D. 1.76 kJ/oC E. 15.3 kJ/oC
C
The combustion of octane produces heat according to the equation: 2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn= ─11,020 kJ What is the heat of combustion per gram of octane? A. 5.510 MJ B. 96.5 kJ C. 48.2 kJ D. 193 kJ E. 629.2 MJ
C
The heat of solution of KCl is 17.2 kJ/mol and the lattice energy of KCl(s) is 701.2 kJ/mol. Calculate the total heat of hydration of 1 mol of gas phase K+ ions and Cl- ions. 718 kJ 684 kJ -684 kJ -718 kJ None of these.
C
The number of resonance structures for the nitrate ion that satisfies the octet rule is a. 1. b. 2. C. 3. d. 4. e. none of these.
C
The specific heat of gold is 0.129 J/g•oC. What is the molar heat capacity of gold (unit is J/mol•oC)? A. 0.039 J/mol•oC B. 0.129 J/mol•oC C. 25.4 J/mol•oC D. 39.0 kJ/mol•oC E. 197 J/mol•oC
C
The total number of lone pairs in the best Lewis structure for the SOF4 molecule is a. 0. b. 2. C. 14. d. 16. e. 18.
C
What is the chemical formula of the salt produced by the neutralization of potassium hydroxide with sulfuric acid? A. KSO3 B. K2(SO4)3 C. K2SO4 D. K(SO4)2 E. KSO4
C
What is the formal charge on the oxygen atom in N2O (the atomic order is N-N-O)? a. 0 b. +1 C. -1 d. -2 e. +2
C
What is the maximum number of grams of ammonia, NH3, that can be obtained from the reaction of 10.0 g of H2 and 80.0 g of N2? N2 + 3H2 2NH3 A. 28.4 g B. 48.6 g C. 56.7 g D. 90.0 g E. 97.1 g
C
When 38.0 mL of 0.1250 M H2SO4 is added to 100. mL of a solution of PbI2, a precipitate of PbSO4 forms. The PbSO4 is then filtered from the solution, dried, and weighed. If the recovered PbSO4 is found to have a mass of 0.0471 g, what was the concentration of iodide ions in the original solution? 1.55 10-3 M 3.10 10-4 M 3.11 10-3 M 1.55 10-4 M 6.20 10-3 M
C
Which choice gives the correct oxidation numbers for all three elements in Ca(ClO)2 in the order that the elements are shown in the formula? A) +2, -2, +1 B) -2, +2, -1 C) +2, +1, -2 D) -2, +3, -2 E) +2, -3, +2
C
Which of the following compounds is a nonelectrolyte? NaOH HNO3 C2H6O (ethanol) KF CH3COOH (acetic acid)
C
Which of these elements has the greatest metallic character? A. Ca B. Mg C. Ba D. As E. Se
C
Which two electron configurations represent elements that would have similar chemical properties? (1) 1s22s22p4 (2) 1s22s22p5 (3) [Ar]4s23d104p3 (4) [Ar]4s23d104p4 A. (1) and (2) B. (1) and (3) C. (1) and (4) D. (2) and (4) E. (2) and (3)
C
A possible set of quantum numbers for the last electron added to complete an atom of germanium in its ground state is A. Row 1. B. Row 2. C. Row 3. D. Row 4. E. Row 5.
C 4 1 -1 +1/2
The distance between carbon atoms in ethylene is 134 picometers. Which of the following expresses that distance in meters?
C. 1.34 10-10 m
The appropriate number of significant figures in the result of 15.234 - 15.208 is
C. 2
Calculate the energy, in joules, required to excite a hydrogen atom by causing an electronic transition from the n = 1 to the n = 4 principal energy level. Recall that the energy levels of the H atom are given by En = -2.18 10-18 J(1/n2) A. 2.07 10-29 J B. 2.19 105 J C. 2.04 10-18 J D. 3.27 10-17 J E. 2.25 10-18 J
C. 2.04 10-18 J
Silicon, which makes up about 25% of Earth's crust by mass, is used widely in the modern electronics industry. It has three naturally occurring isotopes, 28Si, 29Si, and 30Si. Calculate the atomic mass of silicon. Isotope Isotopic Mass (amu) Abundance % 28Si 27.976927 92.23 29Si 28.976495 4.67 30Si 29.973770 3.10
C. 28.0855 amu
What is the name of the acid formed when H2S gas is dissolved in water?
C. hydrosulfuric acid
The S.I. base unit of mass is
C. kg
6.52 The standard enthalpy of formation of glucose, C6H12O6 (s) refers to the ΔH° of which reaction below? 6 CO2(g) + 6 H2O(l) C6H12O6(s) + 6 O2(g) A) A6 CO2(g) + 6 H2O(g) C6H12O6(s) B) BC6H12O6(s) 6 C(graphite) + 3 O2(g) + 6 H2(g) C) C6 C(graphite)) + 3 O2(g) + 6 H2(g) C6H12O6(s) D) DC6H12O6(s) + 6 O2(g) 6 CO2(g) + 6 H2O(1)
D
A 1.375 g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give 1.993 g of carbon dioxide and 0.9519 g of water. The empirical formula of mannitol is A. CHO B. CH7O3 C. C3H2O D. C3H7O3 E. CH2O
D
A 50.0 mL sample of 0.436 M NH4NO3 is diluted with water to a total volume of 250.0 mL. What is the ammonium nitrate concentration in the resulting solution? 21.8 M 0.459 M 2.18 10-2 M 8.72 10-2 M 0.109 M
D
A gold wire has a diameter of 1.00 mm. What length of this wire contains exactly 1.00 mol of gold? [Given: density of Au = 17.0 g/cm3] A. 2630 m B. 3.69 m C. 251 m D. 14.8 m E. 62.7 m
D
A sample of nitrogen gas has a volume of 32.4 L at 20°C. The gas is heated to 220ºC at constant pressure. What is the final volume of nitrogen? 2.94 L 19.3 L 31.4 L 54.5 L 356 L
D
An endothermic reaction causes the surroundings to: A. warm up B. become acidic C. condense D. decrease in temperature E. release CO2
D
Balance the following equation using the smallest set of whole numbers, then add together the coefficients. Don't forget to count coefficients of one. __ SF4 + __ H2O __ H2SO3 + __ HF The sum of the coefficients is A. 4. B. 6. C. 7. D. 9. E. none of these
D
Balance the following equation using the smallest set of whole numbers, then add together the coefficients. Don't forget to count coefficients of one. ___ Al + ___ H2SO4 ___ Al2(SO4)3 + ___ H2 The sum of the coefficients is A. 3. B. 5. C. 6. D. 9. E. 12.
D
Based on the solubility rules, which of the following will occur when solutions of ZnSO4(aq) and MgCl2(aq) are mixed? A) ZnSO4 will precipitate; Mg2+ and Cl- will be spectator ions. B) MgCl2 will precipitate; Zn2+ and SO42- will be spectator ions. C) ZnCl2 will precipitate; Mg2+ and SO42- will be spectator ions. D) No precipitate will form. E) MgSO4 will precipitate; Zn2+ and Cl- will be spectator ions.
D
Based on the solubility rules, which one of the following compounds should be insoluble in water? NaCl MgBr2 FeCl2 AgBr ZnCl2
D
Based on the solubility rules, which one of these compounds should be soluble in water? A. CaSO4 B. BaSO4 C. PbSO4 D. K2SO4 E. AgCl
D
Calculate the enthalpy change for the reaction: 2C8H18(l) + 17O2(g) 16CO(g) + 18H2O(l) ΔHorxn = ? Given: 2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) ΔHorxn = ─11,020 kJ. 2CO(g) + O2(g) 2CO2(g) ΔHof = ─566.0 kJ. A. 10.450 MJ B. 6.492 MJ C. 15.550 MJ D. ─6.492 MJ E. ─10.450 MJ
D
Copper metal has a specific heat of 0.385 J/g•oC and has a melting point of 1083oC. calculate the amount of heat required to raise the temperature of 22.8 g of Cu from 20.0oC to 875oC. A. 1.97 10 ─ 5 J B. 1.0 10 ─ 2 J C. 329 J D. 7.51 kJ E. 10.5 kJ
D
Copper metal has a specific heat of 0.385 J/g•°C. Calculate the amount of heat required to raise the temperature of 22.8 g of Cu from 20.0°C to 875°C. 1.97 10-5 J 1.0 10-2 J 329 J 7.51 kJ 10.5 kJ
D
Estimate the enthalpy change for the reaction 2CO + O2 2CO2 given the following bond energies. BE(CO) = 1074 kJ/mol BE(O=O) = 499 kJ/mol BE(C=O) = 802 kJ/mol a. +2380 kJ/mol b. +744 kJ/mol c. +1949 kJ/mol D. -561 kJ/mol e. -744 kJ/mol
D
From the following data at 25°C: H2(g) + Cl2 2 HCl(g); ΔH° = ─185 kJ 2 H2(g) + O2(g) 2 H2O(g); ΔH° = ─483.7 kJ Calculate ΔH° at 25° for the reaction below: 4 HCl(g) + O2(g) 2 Cl2(g) + 2 H2O(g) A. +114 kJ B. +299 kJ C. ─299 kJ D. ─114 kJ E. ─86.8 kJ
D
Given that: 2 SO3(g) 2 SO2(g) + O2(g); ΔHorxn = +197.8 kJ/mol S(s) + (3/2) O2(g) SO3(g); ΔHorxn = ─395.7 kJ/mol Determine the heat of formation for SO2. A. + 98.9 kJ/mol B. + 197.8 kJ/mol C. +691.8 kJ/mol ─296.8 kJ/mol
D
Given: H2(g) + 1/2O2(g) H2O(l) ΔHof = ─286 kJ What is the enthalpy change for the following reaction? 2H2O(l) 2H2(g) + O2(g) ΔHorxn = ? A. ΔHo = ─286 kJ B. ΔHo = +286 kJ C. ΔHo = ─572 kJ D. ΔHo = +572 kJ E. ΔHo = ─143 kJ
D
Heat is a measure of temperature. a measure of the change in temperature. a measure of thermal energy. a measure of thermal energy transferred between two bodies at different temperature.
D
How many grams of KOH are present in 35.0 mL of a 5.50 M solution? A) 0.193 g B) 1.96 g C) 308 g D) 10.8 g
D
How many moles of Cl atoms are there in 65.2 g CHCl3? A. 0.548 mol B. 1.09 mol C. 3.3 1023 mol D. 1.64 mol E. 3.0 mol
D
If 30.0 mL of 0.150 M CaCl2 is added to 15.0 mL of 0.100 M AgNO3, what is the mass in grams of AgCl precipitate? A) 0.645 g B) 2.64 g C) 0.430 g D) 0.215 g
D
If 325 g of water at 4.2oC absorbs 12.28 kJ, then what is the final temperature of the water? A. 4.21oC B. 4.8oC C. 9.0oC D. 13.2oC E. 2938oC
D
The Lewis structure for a chlorate ion, ClO3-, should show ____ single bond(s), ____ double bond(s), and ____ lone pair(s). a. 2, 1, 10 b. 3, 0, 9 c. 2, 1, 8 D. 3, 0, 10 e. 2, 1, 9
D
The combustion of pentane produces heat according to the equation: C5H12(l) + 8O2(g) 5CO2(g) + 6H2O(l) ΔHorxn= ─3510 kJ How many grams of CO2 are produced per 2500 kJ of heat released? A. 0.0809 g B. 3.56 g C. 31.3 g D. 157 g E. 309 g
D
The concentration of a hydrogen peroxide solution can be conveniently determined by titration against a standardized potassium permanganate solution in an acidic medium according to the following equation: 2MnO4- + 5H2O2 + 6H+ 5O2 + 2Mn2+ + 8H2O If 36.44 mL of a 0.01652 M KMnO4 solution are required to completely oxidize 25.00 mL of a H2O2 solution, calculate the molarity of the H2O2 solution. A) 0.02012 M B) 1.518 × 10-3 M C) 6.023 × 10-4 M D) 0.06020 M
D
The empirical formula of a compound of uranium and fluorine that is composed of 67.6% uranium and 32.4% fluorine is A. U2F B. U3F4 C. UF4 D. UF6 E. UF8
D
The first step in the Ostwald process for producing nitric acid is 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g). If the reaction of 150. g of ammonia with 150. g of oxygen gas yields 87. g of nitric oxide (NO), what is the percent yield of this reaction? A. 100% B. 49% C. 77% D. 33% E. 62%
D
The mass of 1.21 1020 atoms of sulfur is A. 3.88 1021 g. B. 2.00 mg. C. 32.06 g. D. 6.44 mg. E. 2.00 10-4 g.
D
The standard enthalpy of formation of ammonia at 25C is -46.3 kJ/mol. Estimate the N-H bond enthalpy at this temperature. (Given: BE(NN)=941.4 kJ/mol, BE(H-H) = 436.4 kJ/mol) a. 383 kJ/mol b. 475 kJ/mol c. 360 kJ/mol D. 391 kJ/mol e. 459 kJ/mol
D
The stock system name for CrSO3 is: A) chromium sulfur oxide B) chromium(II) sulfate C) chromium sulfide D) chromium(II) sulfite E) chromium(III) sulfite
D
The structures of C2H4 and C2H5OH are The enthalpy change due to the reaction of one mole of C2H4 with water to form C2H5OH can be estimated by a. BE(C=C) - 2BE(C-C) - BE(C-O). b. BE(C=C) + BE(O-H) - 2BE(C-C) - BE(C-O). c. BE(C-O) + BE(C-C) - BE(O-H) - BE(C=C). D. BE(O-H) + BE(C=C) - BE(C-H) - BE(C-O) - BE(C-C). e. BE(C-H) + BE(C-O) + BE(C-C) - BE(O-H) - BE(C=C).
D
Use the Born-Haber cycle to calculate the lattice energy of LiCl(s) given the following data: H(sublimation) Li = 155.2 kJ/mol I1 (Li) = 520 kJ/mol Bond energy (Cl-Cl) = 242.8 kJ/mol EA (Cl) = 348 kJ/mol Hf (LiCl(s)) = -408.8 kJ/mol a. -40 kJ/mol b. 40 kJ/mol c. 736 kJ/mol D. 857 kJ/mol e. 1,553 kJ/mol
D
What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers? ___ Al4C3 + ___ H2O ___ Al(OH)3 + ___ CH4 A. 3 B. 4 C. 6 D. 12 E. 24
D
What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers? ___ Al4C3 + ___ H2O ___ Al(OH)3 + ___ CH4 A. 3 B. 4 C. 6 D. 12 E. 24
D
What is the coefficient preceding O2 when the following combustion reaction of a fatty acid is properly balanced using the smallest set of whole numbers? __ C18H36O2 + __ O2 __ CO2 + __ H2O A. 1 B. 8 C. 9 D. 26 E. 27
D
What is the mass of 7.80 1018 carbon atoms? A. 1.30 10-5 g B. 6.43 103 g C. 7.80 1018 g D. 1.56 10-4 g E. 12.01 g
D
What is the molar mass of Freon-11 gas if its density is 6.13 g/L at STP? 0.274 g/mol 3.64 g/mol 78.2 g/mol 137 g/mol 365 g/mol
D
What mass of K2CO3 is needed to prepare 200. mL of a solution having a potassium ion concentration of 0.150 M? A. 4.15 g B. 10.4 g C. 13.8 g D. 2.07 g E. 1.49 g
D
When 0.7521 g of benzoic acid was burned in a calorimeter containing 1000 g of water, a temperature rise of 3.60oC was observed. What is the heat capacity of the bomb calorimeter, excluding water? The heat of combustion of benzoic acid is ─26.42 kJ/g. A. 15.87 kJ/oC B. 4.18 kJ/oC C. 5.52 kJ/oC D. 1.34 kJ/oC E. 752.1 kJ/oC
D
When solid iron(II) hydroxide is added to water, the resulting solution contains 1.4 10-3 g of dissolved iron(II) hydroxide per liter of solution. What is the hydroxide ion concentration in this solution? A. 7.8 10-6 M B. 1.6 10-5 M C. 2.5 10-10 M D. 3.1 10-5 M E. 4.0 10-3 M
D
Which choice gives the correct oxidation numbers for all three elements in Rb2SO3 in the order that the elements are shown in the formula? A. -2, +6, -2 B. -1, +4, -3 C. +2, +4, -2 D. +1, +4, -2 E. +1, +6, -6
D
Which of the following processes is endothermic? a. O2(g) + 2H2(g) 2H2O(g) b. H2O(g) H2O(l) c. 3O2(g) + 2CH3OH(g) 2CO2(g) + 2H2O(g) d. H2O(s) H2O(l)
D
What is the wavelength of radiation that has a frequency of 2.10 1014 s-1? A. 6.30 1022 m B. 7.00 102 nm C. 7.00 105 m D. 1.43 10-6 m E. 3.00 108 m
D. 1.43 10-6 m
Calculate the wavelength of a neutron that has a velocity of 200. cm/s. (The mass of a neutron = 1.675 10-27 kg.) A. 1.98 10-9 m B. 216 nm C. 1.8 1050 m D. 198 nm E. 5.05 mm
D. 198 nm
A ground-state atom of manganese has ___ unpaired electrons and is _____. A. 0, diamagnetic B. 2, diamagnetic C. 3, paramagnetic D. 5, paramagnetic E. 7, paramagnetic
D. 5, paramagnetic
The number of orbitals in a d subshell is A. 1. B. 2. C. 3. D. 5. E. 7.
D. 5.
The electron in a hydrogen atom falls from an excited energy level to the ground state in two steps, causing the emission of photons with wavelengths of 2624 and 97.2 nm. What is the quantum number of the initial excited energy level from which the electron falls? A. 2 B. 3 C. 4 D. 6 E. 8
D. 6
How many orbitals are allowed in a subshell if the angular momentum quantum number for electrons in that subshell is 3? A. 1 B. 3 C. 5 D. 7 E. 9
D. 7
How many electrons are there in the 2nd principal energy level (n = 2) of a phosphorus atom? A. 3 B. 5 C. 6 D. 8 E. 10
D. 8
The orbital diagram for a ground state carbon atom is A. Row 1. B. Row 2. C. Row 3. D. Row 4.
D. Row 4. updown, updown, up, up, blank, oo
Which of these choices is the electron configuration of an excited state of an iron atom? A. [Ar]4s23d7 B. [Ar]4s23d6 C. [Ar]4s23d8 D. [Ar]4s13d7 E. [Ar]4s13d5
D. [Ar]4s13d7
Lanthanide (or rare earth elements) have atoms or ions with partially filled A. s subshells. B. p subshells. C. d subshells. D. f subshells. E. g subshells.
D. f subshells.
3. Identify the major ionic species present in an aqueous solution of K2SO4. A) K2+, S6+, O48- B) K2+, S6+, 4O2- C) 2K+, S6+, O48- D) 2K+, S6+, 4O2- E) 2K+, SO42-
E
A 0.1326 g sample of magnesium was burned in an oxygen bomb calorimeter. The Htotal heat capacity of the calorimeter plus water was 5760 J/oC. If the temperature rise of the calorimeter with water was 0.570oC, calculate the enthalpy of combustion of magnesium. Mg(s) + 1/2O2(g) MgO(s) A. ─3280 kJ/mol B. ─24.8 kJ/mol C. 435 kJ/mol D. 106 kJ/mol E. ─602 kJ/mol
E
A 100 mL sample of 0.200 M aqueous hydrochloric acid is added to 100 mL of 0.200 M aqueous ammonia in a calorimeter whose heat capacity is 480 J K ─ 1. The following reaction occurs when the two solutions are mixed. HCl(aq) + NH3(aq) NH4Cl(aq) The temperature increase is 2.34oC. Calculate ΔH per mole of HCl neutralized. A. 154 kJ B. 44.5 kJ C. 22.5 kJ D. ─22.5 kJ E. ─56.2 kJ
E
A 100. mL sample of 0.200 M aqueous hydrochloric acid is added to 100. mL of 0.200 M aqueous ammonia in a calorimeter whose heat capacity (excluding any water) is 480. J/K. The following reaction occurs when the two solutions are mixed. HCl(aq) + NH3(aq) NH4Cl(aq) The temperature increase is 2.34°C. Calculate H per mole of HCl and NH3 reacted. 154 kJ/mol 1.96 kJ/mol 485 kJ/mol -1.96 kJ/mol -154 kJ/mol
E
A copper wire has a diameter of 2.00 mm. What length of this wire contains exactly 1.00 mol of copper? [Given: density of Cu = 8.92 g/cm3] A. 0.178 m B. 0.567 m C. 180 m D. 45.1 m E. 2.27 m
E
Aluminum hydroxide reacts with nitric acid to form aluminum nitrate and water. What mass of water can be formed by the reaction of 15.0 g of aluminum hydroxide with excess nitric acid? A) 1.15 g B) 3.46 g C) 45.0 g D) 6.14 g E) 10.4 g
E
Calculate the amount of heat necessary to raise the temperature of 12.0 kg of water from 15.4oC to 93.0oC. A. 0.027 kJ B. 324 kJ C. 389 kJ D. 931 kJ E. 3890 kJ
E
Calculate the work done against an atmospheric pressure of 1.00 atm when 500.0 g of zinc dissolves in excess acid at 30.0oC. Zn(s) + 2H+(aq) Zn2+(aq) + H2(g) A. w = +22.4 kJ B. w = +24.9 kJ C. w = 0 D. w = ─2.52 kJ E. w = ─19.3 kJ
E
Calculate ΔHorxn for the following reaction. 2H2O2(l) 2H2O(l) + O2(g) Use the following information: ΔHof (H2O2(l)) = -187.6 kJ/mol ; ΔHof (H2O(l)) = -285.8 kJ/mol ; ΔHof (O2(g)) = 0 kJ/mol A. 53.0 kJ B. 98.2 kJ C. -98.2 kJ D. 196.4 kJ E. ─196.4 kJ
E
For the reaction: C(s) + O2(g) CO2(g) ΔHof = ─393 kJ How many grams of C(s) must be burned to release 275 kJ of heat? A. 22.3 g B. 0.70 g C. 12.0 g D. 17.1 g E. 8.40 g
E
Given that: S(s) + O2(g) SO2(g); ΔH = ─296.8 kJ/mol 2 SO3(g) 2 SO2(g) + O2(g); ΔH = +197.8 kJ/mol Determine the enthalpy change of the reaction: 2 S(s) + 3O2(g) 2 SO3(g) A. ─99 kJ/mol B. 99 kJ/mol C. 495 kJ/mol D. ─495 kJ/mol ─791.4 kJ/mol
E
How many degrees of temperature rise will occur when a 25.0 g block of aluminum absorbs 10 kJ of heat? The specific heat of Al is 0.900 J/g•oC. A. 0.44oC B. 22.5oC C. 225oC D. 360oC E. 444oC
E
How many degrees of temperature rise will occur when a 25.0 g block of aluminum absorbs 10.0 kJ of heat? The specific heat of Al is 0.900 J/g•°C. 0.44°C 22.5°C 225°C 360°C 444°C
E
If the pressure of a gas sample is quadrupled and the absolute temperature is doubled, by what factor does the volume of the sample change? A) 2 B) 1/8 C) 1/4 D) 8 E) 1/2
E
One mole of iron A. is heavier than one mole of lead (Pb). B. is 77.0 g of iron. C. is 26.0 g of iron. D. weighs the same as one mole of lead. E. is none of these.
E
Since zirconium is a metal, ZrO2 is expected to be a/an _____ oxide. A. acidic B. ionic C. amphoteric D. neutral E. basic
E
The Hall process for the production of aluminum involves the reaction of aluminum oxide with elemental carbon to give aluminum metal and carbon monoxide. If the yield of this reaction is 82% and aluminum ore is 71% by mass aluminum oxide, what mass of aluminum ore must be mined in order to produce 1.0 103 kg (1 metric ton) of aluminum metal by the Hall process? A. 1.8 103 kg B. 2.2 103 kg C. 1.1 103 kg D. 1.6 103 kg E. 3.3 103 kg
E
The combustion of butane produces heat according to the equation: 2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(l) ΔHorxn= ─5314 kJ How many grams of CO2 are produced per 1.00 104 kJ of heat? A. 23.4 g B. 44.0 g C. 82.3 g D. 187 g E. 662 g
E
The element oxygen consists of three naturally occuring isotopes: 16O, 17O, and 18O. The atomic mass of oxygen is 16.0 amu. What can be implied about the relative abundances of these isotopes? A. More than 50% of all O atoms are 17O. B. Almost all O atoms are 18O. C. Almost all O atoms are 17O. D. The isotopes all have the same abundance, i.e. 33.3%. E. The abundances of 17O and 18O are very small.
E
The oxidation number of Fe in K3Fe(CN)6 is A) +2 B) -3 C) -4 D) +1 E) +3
E
The ΔH° of the combustion for methane CH4, is ─890 kJ/mole. How many kg of methane must be burned to supply a house with 2.0 105 kJ daily requirement of energy? A. A2.97 kg B. B535 g C. C60.6 g D. D2.97 g E 3.6 kg
E
Use the bond enthalpy data given to estimate the heat released when 6.50 g of nitrogen gas reacts with excess hydrogen gas to form ammonia at 25C. BE(NN) = 941.4 kJ/mol BE(H-H) = 436.4 kJ/mol BE(N-H) = 393 kJ/mol a. 228 kJ b. 340 kJ c. 107 kJ d. 46.1 kJ E. 24.9 kJ
E
What is the chemical formula of the salt produced by the neutralization of hydrobromic acid with magnesium hydroxide? A) MgBr B) Mg2Br3 C) Mg3Br2 D) Mg2Br E) MgBr2
E
What is the mass of 0.20 mole of C2H6O (ethanol)? A. 230 g B. 46 g C. 23 g D. 4.6 g E. none of these
E
What is the molar mass of nicotine, C10H14N2? A. 134 g/mol B. 148 g/mol C. 158 g/mol D. 210 g/mol E. 162 g/mol
E
What is the theoretical yield of vanadium that can be produced by the reaction of 40.0 g of V2O5 with 40.0 g of calcium based on the following chemical equation? V2O5(s) + 5Ca(l) 2V(l) + 5CaO(s) A. 11.2 g B. 5.6 g C. 22.4 g D. 40.0 g E. 20.3 g
E
When 0.56 g of Na(s) react with excess F2(g) to form NaF(s) at standard state conditions, 13.8 kJ of heat are evolved. What is the standard enthalpy of formation (ΔHof) of NaF(s)? A. 24.8 kJ/mol B. +570 kJ/mol C. ─24.8 kJ/mol D. ─7.8 kJ/mol E. ─570 kJ/mol
E
Which of these elements has the smallest ionization energy? A. Li B. Na C. Be D. K E. Rb
E
Which one of the following reactions occurring at 25oC does the symbol ΔHof[H2SO4(l)] refer to? A. 2H(g) + S(g) + 4O(g) H2SO4(l) B. H2(g) + S(g) + 2O2(g) H2SO4(l) C. H2SO4(l) H2(g) + S(s) + 2O2(g) D. H2SO4(l) 2H(g) + S(s) + 4O(g) E. H2(g) + S(s) + 2O2(g) H2SO4(l)
E
Which one of these ions does not have [Xe] as its electronic configuration? A. Te2- B. I- C. Cs+ D. Ba2+ E. Sn4+
E
Zinc dissolves in hydrochloric acid to yield hydrogen gas: Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g) What mass of hydrogen gas is produced when a 7.35 g chunk of zinc dissolves in 500. mL of 1.200M HCl? 0.605 g 0.113 g 0.302 g 0.453 g 0.227 g
E
Acetic acid boils at 244.2F. What is its boiling point in degrees Celsius?
E. 117.9C
At a pressure of one billionth (10-9) of atmospheric pressure, there are about 2.7 1010 molecules in one cubic centimeter of a gas. How many molecules is this per cubic meter?
E. 2.7 1016
The average distance between the Earth and the Moon is 240,000 miles. Express this distance in kilometers.
E. 3.9 l05 km
A ground-state atom of iron has ___ unpaired electrons and is _____. A. 0, diamagnetic B. 6, diamagnetic C. 3, paramagnetic D. 5, paramagnetic E. 4, paramagnetic
E. 4, paramagnetic
Breaking the oxygen-oxygen bond in hydrogen peroxide requires 210 kJ/mol. What is the longest wavelength of light that can cause this bond to be broken? A. 5.7 10-4 m B. 9.5 10-31 m C. 2.8 10-7 m D. 9.5 10-28 m E. 5.7 10-7 m
E. 5.7 10-7 m
A ground-state chromium atom has how many unpaired electrons? A. 1 B. 2 C. 4 D. 5 E. 6
E. 6
Which of the following compounds is ionic?
E. MgCl2
Which one of the following combinations of names and formulas is incorrect?
E. NaHCO3 sodium carbonate
Tetrasulfur dinitride decomposes explosively when heated. What is its formula?
E. S4N2
The ground-state electron configuration for an atom of indium is A. [Kr]5s24p64d5. B. [Ar]4s23d104p1. C. [Ar]4s24p63d5. D. [Kr]5s25p64d5. E. [Kr]5s24d105p1.
E. [Kr]5s24d105p1.
What is the name of Na2O?
E. sodium oxide
Chemical reactions in a bomb calorimeter occur at constant pressure Conditions.
FALSE
The specific heats of water and iron are 4.184 and 0.444 J/g•oC, respectively. When equal masses of water and iron both absorb the same amount of heat, the temperature increase of the water will be 5.42 times greater than that of the iron.
FALSE
Identify the Brønsted acid in the following reaction. NH3 + H2O NH4+ + OH-
H2O
Batteries in our cars generate electricity by the following chemical reaction. M Pb + PbO2 + 2H2SO4 2PbSO4 + 2H2O What substance is reduced? What is the reducing agent? What substance is oxidized? What is the oxidizing agent?
Pb4+ is reduced, Pb is the reducing agent, Pb is oxidized, PbO2 is the oxidizing agent
A home aquarium is an example of an open system
TRUE
If 2Mg(s) + O2(g) 2MgO(s) ΔHo = ─1203.6 kJ; then for Mg(s) + 1/2O2(g) MgO(s) the enthalpy change is ΔHf = ─601.8 kJ
TRUE
In an endothermic process heat is absorbed by the system.
TRUE
The heat absorbed by a system at constant pressure is equal to ΔE + PΔV.
TRUE
The heat capacity of 20.0 g of water is 83.7 J/oC.
TRUE
The work done on the surroundings by the expansion of a gas is w = ─PΔV.
TRUE
Thorium metal is prepared by reacting thorium oxide with calcium. M ThO2 + 2Ca Th + 2CaO What substance is reduced? What is the reducing agent? What substance is oxidized? What is the oxidizing agent?
Th4+ is reduced, Ca is the reducing agent, Ca is oxidized, ThO4 is the oxidizing agent
What are three characteristics of an acid?
a. Acids taste sour. b. Acids change blue litmus paper to red. c. Acids react with certain metals to produce hydrogen gas .
What are three characteristics of a base?
a. Bases taste bitter. b. Bases feel slippery. c. Bases change change red litmus paper to blue.
Identify each of the following compounds as an electrolyte or nonelectrolyte. E a. NaOH ___________________ b. H2SO4 ___________________ c. methanol ___________________ d. C12H22O11 (sucrose) ___________________ e. MgCl2 ___________________
a. electrolyte b. electrolyte c. nonelectrolyte d. nonelectrolyte e. electrolyte
Identify each of the following compounds as a strong electrolyte, weak electrolyte, E or non electrolyte. a. CH3OH (methanol) ____________________ b. CH3COOH ____________________ c. KNO3 ____________________ d. NH3 ____________________ e. NH4Cl ____________________
a. nonelectrolyte b. weak electrolyte c. strong electrolyte d. weak electrolyte e. strong electrolyte
Describe three situations or conditions in which a reaction will proceed to M completion.
a. reactions in which a precipitate is formed b. reactions in which H2O is formed c. reactions in which a gas is formed
The following equation is an example of a net ionic equation. M Na+ + Br─ + Ag+ + NO3─ AgBr(s) + Na+ + NO3─
f
The oxidation number of N in NO is +7.
f
the following reaction is an acid-base neutralization reaction. E H2SO4(aq) + CaBr2(aq) CaSO4(s) + 2HBr(g)
f
What kind of bonding is found in all salts?
ionic
Identify the following compound as a strong electrolyte, weak electrolyte, or nonelectrolyte: CH3OH (methanol).
nonelectrolyte
Hydrogen is oxidized in the following reaction. M H2 + Cl2 2HCl
t
The oxidation number of iodine increases by 6 in the following reaction. M 2MnO4─ + I ─ + H2O 2MnO2 + IO3─ + 2OH─
t
