Exam 1 chm 113

How many Pop TartsTM are needed to convert 1,000.0 g of water at 20.0°C to 100.0°C? One Pop TartTM is equal to 800,000 J of energy. A) 0.418 B) 2.83 C) 3.25 D) 18.0

a

Given the data in the table below, ΔH°rxn for the following reaction is ______ kJ. Ca(OH)2(s) + 2H3AsO4(aq) à Ca(H2AsO4)2(aq) + 2H2O(l) A) -4219 B) -130.4 C) -4519 D) -76.4

b

Given the equation below, which of the following is true? 2 Mg(s) + O2(g) à 2 MgO(s) + 72.3 kJ A) The reaction is endothermic B) ΔH = -72.3 kJ C) ΔH = +72.3 kJ D) The reaction absorbs heat

b

If 1.45 J of heat are added to a 2.00 g sample of aluminum metal and the temperature of the metal increases by 0.798 °C, what is the specific heat of the aluminum? A) 0.579 J/g°C B) 0.909 J/g°C C) 1.68 J/g°C D) 3.63 J/g°C

b

In the following reaction: CH4 + 3Cl2 à CHCl3 + 3HCl A. CH4 is oxidized and HCl is reduced B. CH4 is oxidized and is Cl2 reduced C. CHCl3 is oxidized and HCl is reduced D. Cl2 is oxidized and CH4 is reduced E. None of the above

b

Select the correct statement. A) w and ΔV have the same sign because the gas expands, work flows into the surroundings B) w and ΔV have the opposite sign because the gas expands, work flows into the surroundings C) w and ΔV have the same sign because the gas expands, work flows out of the surroundings D) w and ΔV have the opposite sign because the gas expands, work flows out of the surroundings

b

What is the concentration of Na2SO4 in a solution if the concentration of Na+ ions is 0.35 M? A. 0.35 M B. 0. 18 M C. 0.12 M D. 1.1 M E. 0.70 M

b

The correct formula for carbonic acid is _____. a) H4C b) HCO3 c) H2CO3 d) H2CO4 e)H3CO3

c

All of the following have standard enthalpy of formation values of zero at 25°C, 1 atm, and 1.0 M concentration except: A) Cl2(g) B) O2(g) C) Na(s) D) All of these have ΔH°f = 0.

d

Which of the following is incorrectly paired? A. H2SO4; strong acid B. NaOH; strong electrolyte C. H3PO4; weak acid D. HClO4; weak electrolyte E. All of the above are correctly paired

d

Which of the following pairs of compounds can be used to illustrate the law of multiple proportions? a) NH4 and NH4Cl b) ZnO2 and ZnCl2 c) H2O and HCl d) NO and NO2 e) CH4 and CO2

d

A student removes 25 mL of 3.0 M NaOH and dilutes it to final volume of 350 mL. What is the concentration of the resulting solution.? A. 42 M B. 0.024 M C. 75 M D. 0.10 M E. 0.21 M

e

An example of an element is ____. a) chicken noodle soup b) powerade c) air inside a balloon d) lead pipe e) baking soda (NaHCO3)

lead pipe

Select the correct statements below. I. Table salt is a good conductor of electricity because it is a strong electrolyte II. Table sugar is a weak conductor of electricity because it is a weak electrolyte III. Methanol, CH3OH, cannot conduct electricity but LiOH can. IV. Acetic acid is a better conductor of electricity than chloric acid. A. I only B. I, III, and IV only C. I and III only D. IIII and IV only E. I, II, IV only

1 and 3 only

Select the correct statements. I. Reduction is the loss of electrons, and oxidation is the gain of electrons II. Reduction is the gain of electrons, and oxidation is the loss of electrons III. The reactant that is reduced is also called the reducing agent, and the reactant that is oxidized is called the oxidizing agent. IV. The reactant that is oxidized is also called the reducing agent, and the reactant that is reduced is called the oxidizing agent. V. The sum of all the oxidation numbers in a compound is equal to the charge of that compound. A. I and III only B. II and IV only C. I, III, and V only D. II, IV, and V only E. V only

2, 4 and 5 only

The specific heat capacity of lead is 0.13 J/g°C. How much heat (in J) is required to raise the temperature of 15 g of lead from 22°C to 37°C? A) 29 B) 5.8 x 10-4 C) -0.13 D) 2.0

29

How many atoms of hydrogen are in ONE molecule of (NH4)2SO4? A. 4 B. 2 C. 6 D. 1 E. 8

8

When dilute HCl is added to a solution, a white precipitate forms. Which ion was likely in the solution? A. Ag+ B. Cu2+ C. Na+ D. Ca2+ E. Sr2+

Ag+

Which of the following is least soluble in water? A. K2CO3 B. KHCO3 C. Ca(HCO3)2 D. CaCO3 E. KNO3

CaCO3

Which of the following contain the same number of electrons? I. Cl- II. Cl III. S IV. S2- V. F- a) I and II only b) I and V only c) II and III only d) I, IV, and V e)I and IV only

1 and 4 only

There are ________ electrons, ________ protons, and ________ neutrons in an isotope of sulfide ion-33. a) 17, 16, 17 b) 18, 16, 16 c) 16, 17, 18 d) 18, 16, 17 e)16, 16, 16

18, 16, 17

The substance in BOX A could represent a sample of _____. a. C and H atoms b) H2O c) NH3 d) CH4 e) H2

H2O

A solution with a total volume of 750. mL contains 37.1 g Mg(NO3)2. Determine the concentration of nitrate ions in solution. A. 0.667 M B. 0.334 M C. 6.67 x 10-4 M D. 3.34 x 10-4 M E. 98.9 M

a

A student reacts 6.0 g solid sulfur and 5.0 g oxygen gas at 95% efficiency to produce sulfur trioxide according to the chemical reaction below. What was the student's actual yield? S8 (s) + 12 O2 (g) à 8 SO3 (g) A. 7.9 g B. 8.3 g C. 14 g D. 15 g E. 11 g

a

Argon has three naturally occurring isotopes: argon-36, argon-38, and argon-40. Based on argon's atomic weight on the periodic table, which isotope is the most abundant in nature? a) Ar-40 b) Ar-38 c) Ar-36 d) All isotopes are equally abundant in nature e) Not enough information is provided.

a

Calculate the density (in g/mL) of an object that has a mass of 12.2 g and occupies a volume of 0.50 m3. a) 2.4 x 10-5 g/mL b) 24 g/mL c) 0.24 g/mL d) 4.1 x 10-2 g/mL e) 4.1 g/mL

a

Calculate ΔHrxn° for 4 NH3(g) + 5 O2(g) à 4 NO(g) + 6 H2O(l) A) -1169 kJ B) +1169 kJ C) -149.3 kJ D) 149.3 kJ

a

Determine the enthalpy of the reaction: S (s) + 3/2 O2 (g) à SO3 (g), given the following reactions. SO2 (g) à S(s) + O2 (g) ΔH = +296.0 kJ 2 SO3 (g) à 2 SO2 (g) + O2 (g) ΔH = +198.2 kJ A) -395.1 kJ B) 494.2 kJ C) 97.8 kJ D) -97.8 kJ

a

How many moles are there in 8.5 x 1025 molecules of CO2? A. 1.4 X 102 mol B. 7.1 X 10-2 mol C. 5.1 X 1049 mol D. 8.5 X 1025 mol E. 4.3 x 1025 mol

a

In a chemical reaction, 3 moles of hydrogen are reacted with 1 mole of nitrogen. Which of the following boxes best represents the product that is produced. A B C D A. Box A B. Box B C. Box C D. Box D E. None of the boxes

a

In a popular television series, the two characters use thermite to assist with breaking into a chemical storage facility because the reaction between aluminum and iron(III) oxide produces a tremendous amount of heat. If they began with 10.0 g of Al, how many kJ of heat would be released? 2 Al(s) + Fe2O3(s) à Al2O3(s) + 2 Fe(s) ΔH = -852 kJ A) 158 kJ B) 236 kJ C) 472 kJ D) None of the above

a

In the following reaction ΔH° = -3351 kJ is __________, and therefore heat is __________ by the reaction. 4Al (s) + 3O2 (g) à 2Al2O3 (s) A) exothermic, released B) exothermic, absorbed C) endothermic, released D) endothermic, absorbed

a

In the following reaction: 2 PbO(s) + O2(g) à 2 PbO2(s) A. PbO is the reducing agent and O2 is the oxidizing agent B. PbO is the reducing agent and PbO2 is the oxidizing agent C. O2 is the reducing agent and PbO is the oxidizing agent D. PbO2 is the reducing agent and PbO is the oxidizing agent E.None of the above

a

Match the reaction type with the reaction (3) A. Combination B. Combustion C. Decomposition D. Neutralization E. Precipitation F. Single-displacement 1. Ba(OH)2 + H2SO4 à 2 H2O + BaSO4 2. Cl2 + 2 NaI à 2NaCl + I2 3. P4 + 10 Cl2 à 4 PCl5 4. H2O2 à H2 + O2

a

Select the correct statement below. a) Ionic compounds form between a metal cation and a anionic non-metal. b) Covalent compounds form between two metals. c) Isotopes of an element have different numbers of electrons. d) Ions of an element have different numbers of neutrons. e)Two different elements can have the same number of protons

a

The correct formula for tetraphosphorous hexasulfide is _____. a) P4S6 b) PS c) P3S6 d) P4S7 e) PS6

a

The dissociation of a salt in water to from an aqueous solution is called enthalpy of solution, ΔHsoln. The ΔHsoln for CaCl2 is -120 kJ/mol. When CaCl2 is added to water _____. A) the temperature of the water will increase. B) the temperature of the water will remain the same. C) the process is endothermic. D) nothing will occur, CaCl2 is insoluble.

a

Water has a specific heat of 4.184 J/g°C while glass (Pyrex) has a specific heat of 0.780 J/g°C. If 10.0 J of heat is added to 1.00 g of each of these, which will experience the larger increase of temperature? A) glass B) water C) they both will experience the same change in temperature since only the amount of a substance relates to the increase in temperature. D) Not enough information is provided.

a

What are the signs for q and w if a system absorbs 180 J of heat energy while expanding against constant pressure? A) +q and -w B) +q and +w C) -q and -w D) -q and +w

a

What is the change in internal energy for a system undergoing an endothermic process in which 29.2 kJ of heat flows and where 3.70 kJ of work is done on the system? A) 32.9 kJ B) 108 kJ C) 25.5 kJ D) 7.89 kJ

a

Which of the following represents a standard enthalpy of formation reaction? A) C(s) + O2 (g) à CO2 (g) B) 2Na (s) + Cl2 (g) à 2NaCl (s) C) MgO (s) + H2O (l) à Mg(OH)2 (s) D)All of the above are standard enthalpy of formation reactions

a

Which one of the following is not one of the postulates of Dalton's atomic theory? a) Atoms are composed of protons, neutrons, and electrons. b) All atoms of a given element are identical; the atoms of different elements are different and have different properties. c) Atoms of an element are not changed into different types of atoms by chemical reactions: atoms are neither created nor destroyed in chemical reactions. d) Compounds are formed when atoms of more than one element combine; a given compound always has the same relative number and kind of atoms. e) Each element is composed of extremely small particles called atoms.

a

a) measured number b) exact number c) accuracy d) precision e) none of the above 18. A BMI of 21 is an example of _____.

a

An example of a pure substance is ____. a) an element b) a compound c) H2O d) carbon dioxide e) all of these

all of these

The correct name of Al2(CO3)3 is _____. a) aluminum(III) carbonite b) aluminum(III) carbonate c) aluminum carbide d) aluminum carbonite e)aluminum carbonate

aluminum carbonate

A 24.6 g sample of a metal is heated to 110.0°C and then placed in a coffee cup calorimeter containing 125 g of water at a temperature of 23.00°C. After the metal cools, the final temperature of the metal and water is 24.83°C. Assuming no heat has escaped to the surroundings or been absorbed by the calorimeter, calculate the specific heat of the metal. A) 4.18 J/g°C B) 0.457 J/g°C C) 0.499 J/g°C D)1.00 J/g°C

b

All of the following are in aqueous solution. Which is incorrectly named? a) HC2H3O2, acetic acid b) HBr, bromic acid c) H2SO3, sulfurous acid d) HNO2, nitrous acid e) HClO3, chloric acid

b

Bath salts such as Epsom contain hydrate salts such as MgSO4·7H2O (magnesium sulfate heptahydrate). When heated, water is released as vapor and anhydrous MgSO4 remains. Determine how many moles of vapor are released when 15.5 g of MgSO4·7H2O are heated. Hint: Include H2O when calculating the molar mass. A. 0.291 mol B. 0.440 mol C. 0.253 mol D. 0.0629 mol E. 0.129 mol

b

Calculate the mass of an object that has a volume of 100.0 L and a density of 1.00 g/mL. a) 100. g b) 1.00 x 105 g c) 1.00 x 103 g d) 1.00 x 10-2 g e) 1.00 g

b

Calculate the volume of silver metal that weighs exactly 2.50 kg. The density of silver is 10.5 g/cm3. a) 0.238 mL b) 238 mL c) 26.3 mL d) 4.20 mL e) 0.00420 mL

b

Calculate the work done (in J) when a gas condenses from 971 mL to 264 mL at a constant pressure of 4.00 atm. A) +2.83 J B) +286 J C) -2.83 J D) -286 J

b

For a particular process, the system releases 17 kJ of heat and has 21 kJ of work performed on it. Which of the following statements is false? A) Heat flows from the system to the surroundings B) The system does work on the surroundings C) ΔE = +4 KJ D) The process is exothermic

b

Select the endothermic reaction. A) CH4(s) + O2(g) à CO2(g) + 2 H2O(l) + 890 kJ B) 2 HCl(g) + 185 kJ à H2(g) + 2 Cl2(g) C) 4 NH3(g) + 5 O2(g) à 4 NO (g) + 6 H2O(l) ΔH = -1169 kJ D)None of the reactions are endothermic

b

Select the exothermic reaction. A) 4CO(g) + Fe3O4(s) 3Fe(s) + 4CO2(s) à ∆H = +12.5 kJ B) 4 NH3(g) + 5 O2(g) à 4 NO (g) + 6 H2O(l) + 1169 J C) CO2(g) + 2 H2O(l) + 890 kJ à CH4(s) + O2(g) D) 2 HCl(g) + 185 kJ à H2(g) + 2 Cl2(g)

b

Select the incorrect statement. A) Specific heat capacity can never be a negative value. B) Specific heat capacity of a substance is the amount of energy required to increase the temperature of 1 g of that substance by 1°F. C) Specific heat capacity is a larger value when more energy is required to change the temperature of that substance. D) More than one statement is incorrect.

b

Select the incorrect statement. A) w is positive when work is done on the system B) w = PΔV C) The unit for w is Joules D) w is the symbol for work

b

Select the incorrectly matched pair for unit and dimension. a) Time - seconds b) Amount of substance - grams c) Mass - kilograms d) Length - meters e) Volume - cubic centimeters

b

The _____ states that the total mass of materials present after a chemical reaction is the same as the total mass present before the reaction. a) Dalton's atomic theory b) law of conservation of mass c) law of multiple proportions d) law of constant composition e)none of the above

b

The element X has three naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. The average atomic mass of the element is ________ amu. a) 219.7 b) 220.4 c) 220.9 d) 218.5 e) 221.0

b

The heat of combustion for 1.00 mole of carbon to carbon dioxide is -410. kJ. How many kJ of heat would be liberated from the complete combustion of 60.0 g of carbon? A) -82.0 kJ B) -2050 kJ C) -24,600 kJ D) -879 kJ

b

The image below shows the reaction between hydrogen and chlorine gas. Based on the starting amounts provided for the reactants, select the true statement below. A. Cl2 is the limiting reactant because it is present in the lesser amount B. Cl2 is the limiting reactant because it is completely consumed during the reaction C. H2 is the limiting reactant because it is present in excess after th reaction D. H2 is the limiting reactant because it is present in a lesser amount E.None of the statements are true

b

Using standard enthalpies of formation, calculate the heat of hydrogenation of acetylene gas, C2H2(g), to form ethane gas. C2H2(g) + 2H2(g) à C2H6(g) A) 142.1 kJ B) -311.46 kJ C) -142.1 kJ D) +311.46 kJ

b

What is the change in internal energy for a system that performs 213 kJ of work on its surroundings and loses 79 kJ of heat in the process. A) +292 J B) -292 kJ C) +152 J D) -152 J

b

What volume of water must be added to 300 mL of 0.75 M HCl to dilute the solution to 0.25 M? A. 900 mL B. 600 mL C. 300 mL D .930 mL E.100 mL

b

Which of the following equations is not balanced? A. C6H12O6 + 6 O2 à 6 CO2 + 6 H2O B. C2H5OH(l) + 3 O2(g) à 2 CO2(g) + 2 H2O(g) C. C2H4(g) + 3 O2(g) à 2 CO2(g) + 2 H2O(g) D. C3H8(l) + 5 O2(g) à 3 CO2(g) + 4 H2O(g) E. C3H6O(l) + 4 O2(g) à 3 CO2(g) + 3 H2O(g)

b

Which of the following metric relationships is incorrect? a) 1 microliter = 10-6 liters b) 1 gram = 103 kilograms c) 103 milliliters = 1 liter d) 1 gram = 102 centigrams e) 10 decimeters = 1 meter

b

a) measured number b) exact number c) accuracy d) precision e) none of the above 17. A dozen doughnuts is an example of _____.

b

An example of a compound is _____. a) chicken noodle soup b) powerade c) air inside a balloon d) lead pipe e) baking soda (NaHCO3)

baking soda

2.0 ng is equal to a) 2.0 x 10-7 g b) 2 x 103 g c) 2.0 x 10-9 g d) 2.0 x 109 g e) 2.0 x 107 g

c

Calculate the standard enthalpy of formation of solid calcium carbide. CaC2(s) + 2 H2O(1) à Ca(OH)2(s) + C2H2(g) ΔH°rxn = - 129.9 kJ/mol A) +966.7 kJ/mol B) -966.7 kJ/mol C) -58.1 kJ/mol D)+58.1 kJ/mol

c

Determine the enthalpy of the reaction: 3Fe2O3 (s) + CO (g) à CO2 (g) + 2Fe3O4 (s), given the following reactions. Fe2O3 (s) + 3CO (g) à 2Fe (s) + 3CO2 (g) ∆H = -28.0 kJ 3Fe (s) + 4CO2 (s) à 4CO (g) + Fe3O4 (s) ∆H = +12.5 kJ A) 40.5 B) +109 C) -59.0 D) -109

c

Determine the enthalpy of the reaction: N2 (g) + O2 (g) à 2NO (g), given the following reactions. N2 (g) + 2O2 (g) à 2NO2 (g) ΔH = 66.4 kJ 2NO (g) + O2 (g) à 2NO2 (g) ΔH = -114.2 kJ A) -47.8 B) 47.8 C) 180.6 D) 90.3

c

How many grams of water (4.184 J/g°C) can be heated from 20.0 °C to 75.0°C using 12.5 kJ? A) 2880 g B) 5.43 x 103 g C) 54.3. g D) -54.3. g

c

How many hydrogen atoms are in 4 molecules of isopropyl alcohol, C3H7O? A. 2.4 x 1023 atoms of H B. 4 atoms of H C. 28 atoms of H D. 1.7 x 1025 atoms of H E. 7 atoms of H

c

Match the reaction type with the reaction (4) A. Combination B. Combustion C. Decomposition D. Neutralization E. Precipitation F. Single-displacement 1. Ba(OH)2 + H2SO4 à 2 H2O + BaSO4 2. Cl2 + 2 NaI à 2NaCl + I2 3. P4 + 10 Cl2 à 4 PCl5 4. H2O2 à H2 + O2

c

Perform the indicated mathematical operation and round the answer to the correct number of significant figures. 4201.5 - 0.08 + 181/0.544 = a) 4530 b) 4534.14 c) 4534 d) 4534.1 e) 4500

c

Select the correct answer below given the following numbers. 4250600 0.0560030 Significant Figures Scientific Notation Significant Figures Scientific Notation a) 5 4.2506 x 106 5 5.6003 x 10-2 b) 4 4.251 x 106 8 5.60030 x 10-2 c) 5 4.2506 x 106 6 5.60030 x 10-2 d) 5 4.2506 x 104 3 5.63 x 10-2 e) 6 4.25060 x 106 7 5.6003 x 10-2

c

Select the correctly paired empirical and molecular formulas Molecular Empirical A. C3H2 CH B. C6H2 C2H C. C3H2OH C3H2OH D. C6H12 C2H4 E. C4H8 C2H4

c

Select which of the following substances would require the least amount of energy to increase 20.0 g by 20°C. A) Methanol B) Ethanol C) Acetone D) All substances would behave the same

c

The _____ states that if two elements A and B combine to form more than one compound, the masses of B that can combine with a given mass of A are in the ratio of small whole numbers. a) Dalton's atomic theory b) law of conservation of mass c) law of multiple proportions d) law of constant composition e) none of the above

c

The common fertilizer NH4NO3(s), can explosively decompose according to the following reaction. What is the heat released when 80.06 g of NH4NO3(s) explodes? Molar mass of NH4NO3(s) = 80.06 g/mol. 2 NH4NO3(s) à 2 N2(g) + O2(g) + 4 H2O (g) ΔH = -236.15 kJ A) -472.3 kJ B) -236.15 kJ C) -118.08 kJ D) -59.04 kJ

c

The correct name for CuN is _____. a) copper(III) nitrate b) copper(I) nitrate c) copper(III) nitride d) copper(I) nitride e) copper mononitride

c

The value of ΔH° for the reaction below is -336 kJ. Calculate the heat (kJ) released to the surroundings when 23.0 g of HCl is formed. CH4 (g) + 3Cl2 (g) à CHCl3 (l) + 3HCl (g) A) 211 B) 177 C) 70.7 D) -336

c

Using the image, select the chemical equation that best represents the balanced chemical reaction (using smallest whole number coefficients). A. X2 + YX -> YX2 B. 2 X2 + 4 YX -> 4 YX2 C. X2 + 2 YX -> 2 YX2 D. Y2 + YX à Y2X E. None of the above

c

What is the change in internal energy of a system that has 682 J of work done on it and gives off 485 J of heat? A) +1167 J B) -1167 J C) +197 J D) -197 J

c

What is the percent by mass of carbon in acetone, C3H6O? A. 1.60 % B. 30.0 % C. 62.0 % D. 20.7 % E. 50.0 %

c

What volume of 3.0 M NaOH can be prepared using exactly 96.0 g of NaOH? A. 0.14 L B. 0.70 L C. 0.80 L D. 1.25 L E. 7.20 L

c

Which of the following pairs is incorrect? a) NH4Br, ammonium bromide b) K2CO3, potassium carbonate c) BaPO4, barium phosphate d) CuCl, copper(I) chloride e) MnO2, manganese(IV) oxide

c

Which of the following statements are incorrect? a) The state of matter for an object that has a definite volume but not a definite shape is a liquid state b) The state of matter for an object that has both definite volume and definite shape is solid state c) The state of matter for an object that has a definite shape and is highly compressible is gaseous state d) The state of matter for an object that has no definite volume and takes the shape of its container is gaseous state e) The state of matter for an object that is rigid is solid state

c

a) measured number b) exact number c) accuracy d) precision e) none of the above 16. How close a measured number is to the true value is _____.

c

An example of a heterogeneous mixture is _____. a) chicken noodle soup b) powerade c) air inside a balloon d) lead pipe e) baking soda (NaHCO3)

chicken noodle soup

424 Kelvin equals a) 151 °F b) 273 °F c) 697 °F d) 151 °C e) 697 °C

d

65.2°F is equal to _____ °C. a) 36.2 b) 4.20 c) 33.2 d) 18.4 e) 60.0

d

A chunk of iron at 90.6°C was added to 200.0 g of water at 15.5°C. The specific heat of iron is 0.449 J/g°C, and the specific heat of water is 4.184 J/g°C. The temperature of the resulting mixture was 18.2°C. Assuming no heat was lost to the surroundings, what was the mass of the iron added? A) 468 g B) 55.5 g C) 66.9 g D) 69.5 g

d

Aspirin (C9H8O4) may be synthesized by mixing salicylic acid (C7H6O3) with excess acetic anhydride (C4H6O3). When 2.0 g of salicylic acid is mixed with excess acetic anhydride, 1.7 g of aspirin is collected. What is the percent yield of this reaction? The balanced equation is C7H6O3 + C4H6O3 à C9H8O4 + C2H4O2 A. 98 % B. 85 % C. 77 % D. 65 % E. 55 %

d

Calculate the work done by a system when a piston expands from a volume of 13.27 L to 76.55 L against a pressure of 14.89 atm? A) -9.545 J B) -4.250 J C) -63.28 J D) -95450 J

d

Consider the following numbered processes to calculate ΔH for the process: A à 2C + E A à 2B ΔH1 B à C + D ΔH2 E à 2D ΔH3 A) ΔH1 + ΔH2 + ΔH3 B) ΔH1 + ΔH2 C) ΔH1 + ΔH2 - ΔH3 D) ΔH1 + 2 ΔH2 - ΔH3

d

How many carbon atoms are in 0.550 mol of isopropyl alcohol (C3H7O)? A. 3.31 x 1023 atoms of C B. 1.65 atoms of C C. 3 atoms of C D. 9.94 x 1023 atoms of C E. 189 atoms of C

d

Match the reaction type with the reaction (1) A. Combination B. Combustion C. Decomposition D. Neutralization E. Precipitation F. Single-displacement 1. Ba(OH)2 + H2SO4 à 2 H2O + BaSO4 2. Cl2 + 2 NaI à 2NaCl + I2 3. P4 + 10 Cl2 à 4 PCl5 4. H2O2 à H2 + O2

d

Select the correct statement below. A. The percent composition (by mass) is the same for each element in that compounds empirical and molecular formulas. B. Three different compounds having the same percent composition and the same molar mass will also have the same empirical formula. C. An element with the largest atomic mass is always the element present in the highest percentage by mass in a compound. D. A and B are correct E. A, B, and C are correct

d

Select the correct statement. A) In an exothermic reaction, the surroundings releases heat. B) If the sign of w is negative, the reaction is always exothermic. C) If ΔE is negative, the reaction is always exothermic. D) When the surroundings gains heat, the reaction is exothermic.

d

Select the incorrect statement below. a) Cations are positively charged ions. b) Anions are negatively charged ions. c) Atoms that gain an electron are called anions. d) Atoms that gain a neutron are called cations. e) All statements are correct.

d

Select the incorrect statement. A) q is the symbol for heat B) q = mCsΔT C) The unit for q is Joules D) q is positive when the system releases heat

d

The _____ states that the relative number of atoms of each element in the compound is the same in any sample. a) Dalton's atomic theory b) law of conservation of mass c) law of multiple proportions d) law of constant composition e) none of the above

d

The products of a combustion reaction are shown in the diagram in the exact quantities after the chemical reaction. Determine the chemical formula of the molecule that reacts with oxygen. A. CH4 B. C2H6 C. C4H10 D. C6H12O6 E. C5H12

d

To which of the following reactions occurring at 25°C does the symbol ΔH°f [H2O(l)] apply? A) H2O(l) à 2 H(g) + O(g) B) 2 H(g) + O(g) à H2O(l) C) H2(l) + ½ O2(g) à H2O(l) D) H2(g) + ½ O2(g) à H2O(l)

d

What is the empirical formula of a compound that is 3.05% carbon, 0.26% hydrogen, and 96.69% iodine? A. C2HI7 B. CH2I5 C. C3H2I11 D. CHI3 E. CHI

d

What is the maximum amount of Al2Cl6 that can be formed from the reaction of 4.0 mol of Al with 5.0 mol of Cl2 according to this equation? 2 Al(s) + 3 Cl2(g) à Al2Cl6(s) A. 9.0 mol B. 3.7 mol C. 2.0 mol D. 1.7 mol E.5.2 mol

d

What is the molar mass of (NH4)2SO4? A. 113.19 g/mol B. 124.21 g/mol C. 141.39 g/mol D. 132.17 g/mol E. 114.05 g/mol

d

What is the percent by mass of oxygen in Ca(OH)2? A. 40.0 % B. 33.3 % C. 36.3 % D. 43.2 % E. 28.0 %

d

What is the total mass, in grams, of products when 2.20 g of propane is burned in excess oxygen according to the balanced chemical reaction below? C3H8 + 5O2 à 3CO2 + 4H2O A. 2.20 g B. 3.60 g C. 6.60 g D. 10.2 g E. 44.1 g

d

What volume of 17.4 M HCl should be used to prepare 500. mL of a 6.00 M solution of HCl? A. 1450 mL B. 209 mL C. 0.209 mL D. 172 mL E. 2.9 mL

d

When a solution of magnesium nitrate is mixed with a solution of sodium phosphate, the solid that forms is magnesium phosphate. Select the equation that represents the net ionic equation. A. Mg(NO3)2(aq) + Na2PO4(aq) à MgPO4(s) + NaNO3(aq) B. Mg2+(aq) + PO43-(aq) à MgPO4(s) C. 3Mg(NO3)2(aq) + 2Na3PO4(aq) à Mg3(PO4)2(s) + 6NaNO3(aq) D. 3Mg2+(aq) + 2PO43-(aq) à Mg3(PO4)2(s) E. 3Mg2+(aq)+6NO3-(aq) + 6Na+(aq) + 2PO43-(aq) àMg3(PO4)2(s)+6NO3-(aq)+ 6Na+(aq)

d

a) measured number b) exact number c) accuracy d) precision e) none of the above 15.How close a measured number is to other measured numbers is _____

d

A compound has an empirical formula of C2H2O. If the experimental molecular weight is found to be ~170 g/mol, the molecular formula of the compound is: A. C3H6O3 B. C2H2O C. C4H4O2 D. C6H6O3 E. C8H8O4

e

How many grams are required to create 350. mL of a 1.42 M NaCl solution? A. 237 g B. 0.237 g C. 8.50 x 10-3 g D. 5.99 g E.29.0 g

e

Select the incorrectly paired identification of each box above. a) Box A contains 12 atoms and 4 molecules of 1 compound. b) Box B contains 19 atoms from two different elements. c) Box C contains 7 molecules and only one type of compound. d) Box D contains a diatomic molecule and a total of 14 atoms of the same element. e)Box E contains 4 molecules of one compound and a total of 19 atoms

e

Select the incorrectly paired items. a) Li and Na are alkali metals b) Ca and Ba are alkaline earth metals c) Cl and Br are halogens d) F and Ne are in the same period e) S and P are in the same group

e

The correct formula for hydroiodic acid is _____. a) HIO4 b) HIO3 c) HIO2 d) HIO e) HI

e

The image below represents the reactants used to produce ammonia. Determine how many moles of hydrogen are required to produce 13.0 mol of the product. You must first determine the balanced chemical reaction - the amounts in the image are not exact. A. 4.00 mol B. 10.0 mol C. 39.0 mol D. 6.50 mol E. 19.5 mol

e

What is the correct nuclear symbol for a neutral atom of sodium with a mass number of 20 and 10 electrons? a) 22Na+ b) 11Na+ c) 20Na d) 22Na e) 20Na+

e

When a solution of magnesium nitrate is mixed with a solution of sodium phosphate, the solid that forms is magnesium phosphate. Select the equation that represents the complete ionic equation. A. Mg(NO3)2(aq) + Na2PO4(aq) à MgPO4(s) + NaNO3(aq) B. Mg2+(aq) + PO43-(aq) à MgPO4(s) C. 3Mg(NO3)2(aq) + 2Na3PO4(aq) à Mg3(PO4)2(s) + 6NaNO3(aq) D. 3Mg2+(aq) + 2PO43-(aq) à Mg3(PO4)2(s) E. 3Mg2+(aq)+6NO3-(aq) + 6Na+(aq) + 2PO43-(aq) àMg3(PO4)2(s)+6NO3-(aq)+ 6Na+(aq)

e

Which solution will produce a precipitate when mixed with a solution of Ba(NO3)2? A. CuCl2(aq) B. NaCH3CO2(aq) C. NaCl(aq) D. NH4I(aq) E. (NH4)2SO4(aq)

e

When C4H8O4, tetrose, dissolves in water A. each C4+, H+, and O2- ion is surrounded by water B. each CH and OH- particles are surrounded by water C. each CH and OH particles are surrounded by water D. each C4H8O4 molecule is surrounded by water E. tetrose does not dissolve in water

each C4H8O4 molecule is surrounded by water

When Na2SO4(s) dissolves in water, A. each of the Na, S, and O atoms is surrounded by water. B. each of the Na+ and SO4^2- ions is surrounded by water. C. each Na atom and SO4 molecule is surrounded by water. D. each Na2SO4 unit is surrounded by water. E. each Na+, S2-, and O2- ion is surrounded by water.

each of the Na+ and SO4^2- ions is surrounded by water

Match the reaction type with the reaction (2) A. Combination B. Combustion C. Decomposition D. Neutralization E. Precipitation F. Single-displacement 1. Ba(OH)2 + H2SO4 à 2 H2O + BaSO4 2. Cl2 + 2 NaI à 2NaCl + I2 3. P4 + 10 Cl2 à 4 PCl5 4. H2O2 à H2 + O2

f

A(n) _______ is formed after an observation and attempts to provide a testable explanation of an observed behavior of some natural phenomenon. a) observation b) hypothesis c) theory d) law e) scientific method

hypothesis

When nature behaves in a certain way over and over again, under all sorts of different conditions, we can summarize that behavior (typically a relationship), it is called a(n) _____. a) observation b) hypothesis c) theory d) law e) experiment

law

The correct name for LiCl is a) lithium monochloride b) lithium(I) chloride c) monolithium chloride d) lithium chloride e) monolithium monochloride

lithium chloride

An example of a homogeneous mixture is _____. a) chicken noodle soup b) powerade c) the helium inside a balloon d) lead pipe e) baking soda (NaHCO3)

powerade

Which of the following atoms has an oxidation number of +6 in H2SO4? A. H B. S C. O D. Both S and O E. None of the atoms

s

A(n) _____ is a model that is based on a set of tested hypotheses and gives an overall explanation of some natural phenomenon. a) observation b) hypothesis c) theory d) law e) measurement

theory

What precipitate(s) form when mixing aqueous solutions of Ca2+, Cl-, CO32-, and NO3-. A. CaCO3 B. CaCO3 and CaCl2 C. Ca(NO3)2, CaCO3, and CaCl2 D. Ca(NO3)2 and CaCl2 E.No precipitates will form

CaCO3

What is the oxidation number of Cr in Cu2CrO4? A. +12 B. +3 C. +4 D. +5 E. +6

+6

The anion in Al2(CO3)3 has a charge of _____. a) + 3 b) -3 c) -2 d) -1 e) it is neutral (no charge)

-2

How many carbonite ions are in one formula unit of Al2(CO3)3? a) 0 b) 1 c) 2 d) 3 e) 9

0

Which of the following statements about the atomic structure of an atom is false? I. An atom is mostly empty space. II. Almost all of the mass of the atom is concentrated in the nucleus. III. The protons and neutrons in the nucleus are very tightly packed. IV. The number of protons and neutrons is always the same for all neutral atoms of that element. V. Ions are formed by adding or removing either protons or electrons. a) I, II, and III only b) IV and V only c) V only d) I and V only e) All statements are true, no statements are false.

4 and 5 only

Select the correct set of coefficients for the balanced chemical reaction using smallest whole number coefficients. RbOH(aq) + Al2(SO4)3(aq) à Rb2SO4(aq) + Al(OH)3(s) A. 1, 1, 1, 1 B. 3, 1, 2, 2 C. 3, 1, 3, 1 D. 6, 1, 3, 2 E. 12, 1, 12, 6

6, 1, 3, 2

Select the correct statement below that fits a theoretical yield when a reaction between equal masses of Ca and O occurs to produce CaO. A. The mass of CaO produced equals the sum of the starting masses of Ca and O B. The mass of CaO produced is more than the sum of the masses of Ca and O C. The mass of CaO produced is less than the sum of the masses of Ca and O D. There is not enough information to complete this question E. None of the answer choices are correct

The mass of CaO produced equals the sum of the starting masses of Ca and O