Chemistry Chapter 6 & 7 (BC)

A compound composed of only carbon and hydrogen is 25.2% hydrogen by mass. The empirical formula for this compound is: A) CH 0.25 B) C3H C) CH4 D) C2H8 E) none of the above

CH4

23) Which of the following compounds is INSOLUBLE? A) magnesium phosphate B) magnesium sulfate C) magnesium iodide D) magnesium nitrate E) none of the above

magnesium phosphate

How many moles of bromine gas are in 37.7 grams? A) 0.236 B) 0.472 C) 3.01 × 103 D) 79.9 E) none of the above

0.236

How many moles of Pb are in 4.71 × 1021 Pb atoms? A) 0.00782 B) 2.84 × 1045 C) 207.2 D) 6.022 × 1023 E) none of the above

0.00782

What is the mass of 1.56 × 1021 atoms of magnesium in grams? A) 4.72 × 10-5 B) 0.0630 C) 0.142 D) 1.07 × 10-4 E) none of the above

0.0630

How many moles are there in 17.5 grams of sodium? A) 22.99 B) 1.05 × 1025 C) 0.761 D) 1.31 E) none of the above

0.761

Determine the correct empirical formula of a compound containing 26.68% carbon, 2.24% hydrogen, and 71.08% oxygen. A) CHO B) CHO2 C) C0.5H0.5O1 D) C2H2O4 E) none of the above

CH02

How many hydrogen atoms are in 35.0 grams of hydrogen gas? A) 4.25 × 1025 B) 2.09 × 1025 C) 2.12 × 1025 D) 1.05 × 1025 E) none of the above

1.05 x 1025

How many moles are there in 82.5 grams of iron? A) 4.97 × 1025 B) 55.85 C) 0.677 D) 1.48 E) none of the above

1.48

How many atoms of lithium are in 18.7 g? A) 2.14 x 1024 B) 2.70 x 1024 C) 1.62 x 1024 D) 3.11 x 1024 E) none of the above

1.62 x 1024

How many atoms are in 1.50 moles of fluorine gas? A) 6.022 × 1023 B) 9.03 × 1023 C) 18.98 D) 1.81 × 1024 E) none of the above

1.81 x 1024

If a sample of carbon dioxide contains 3.8 moles of oxygen atoms, how many moles of carbon dioxide are in the sample? A) 1.9 B) 3.8 C) 7.6 D) 11.4 E) none of the above

1.9

One mole of boron has a mass of ________ g. A) 9.012 B) 6.022 × 1023 C) 5 D) 10.811 E) none of the above

10.811

What is the mass percent of hydrogen in water? A) 33.3 B) 88.8 C) 5.60 D) 11.2 E) none of the above

11.2

An iron ore sample is found to be 35.00% Fe by mass. How many grams of ore are needed to obtain 454g of Fe? A) 1297 B) 158.9 C) 295.1 D) 350.0 E. none of the above

1297

How many moles of oxygen are in 3.30 moles of NaC? A) 3.30 B) 0.303 C) 19.0 D) 13.2 E) none of the above

13.2

A 42.7 gram sample of potassium nitrate contains how many grams of potassium? A) 39.1 B) 16.5 C) 21.4 D) 8.54 E) none of the above

16.5

Calculate the molar mass of calcium nitrate. A) 136.03 g/mol B) 102.09 g/mol C) 132.10 g/mol D) 164.10 g/mol E) none of the above

164.10 g/mol

What is the mass of 3.09 × 1024 atoms of sulfur in grams? A) 9.64 × 1022 B) 9.91 × 1025 C) 165 D) 0.160 E) none of the above

165

How many moles of fluorine are in 3.2 moles of xenon hexafluoride? A) 22.4 B) 12.8 C) 19.2 D) 16 E) none of the above

19.2

An estrogen compound with the empirical formula C12H17O2 has a molecular mass of 386.6 g/mol. What is the value of n necessary to find the molecular formula? A) 0.2 B) 1 C) 2 D) 20 E) none of the above

2

One mole of ammonium nitrate contains: A) 3 moles of hydrogen. B) 2 moles of oxygen. C) 2 moles of nitrogen. D) 1 mole of nitrogen. E) none of the above

2 moles of nitrogen

What are the coefficients for the following reaction when it is properly balanced? ___HCl + ___Mg → ___MgCl2 + ___H2 A) 2, 1, 1, 1 B) 2, 1, 2, 2 C) 1, 2, 1/2, 1 D) 1, 1, 1, 2 E) none of the above

2, 1, 1, 1

What are the coefficients for the following reaction when it is properly balanced? ___O2 + ___CH4 → ___CO2 + ___H2O A) 2, 1, 3, 1 B) 2, 3, 2, 2 C) 1, 3, 2, 1 D) 2, 1, 1, 2 E) none of the above

2, 1, 1, 2

What are the coefficients for the following reaction when it is properly balanced? ___Na3PO4 + ___Ba(NO3)2 → ___NaNO3 + ___Ba3(PO4)2 A) 2, 1, 1, 3 B) 2, 3, 1, 6 C) 2, 3, 6, 1 D) 6, 1, 3, 2 E) none of the above

2, 3, 6, 1

Bananas cost 33¢ per pound. If you spent $0.77, how many pounds of bananas did you purchase? A) 2.33 B) 1.73 C) 0.429 D) 2.01 E) none of the above

2.33

Given that sodium chloride is 39.0% sodium by mass, how many grams of sodium chloride are needed to have 950 mg of Na present? A) 2.44 B) 0.371 C) 2,430 D) 37.1 E) none of the above

2.44

How many atoms are present in 4.5 moles? A) 3.7 x 1023 B) 3.7 x 10-25 C) 2.7 x 1024 D) 6.02 x 1023 E) none of the above

2.7 x 1024

What is the mass of 3.91 x 1024 sulfur atoms? A) 208 B) 4.93 C) 155 D) 32.07 E) none of the above

208

What is the mass (in grams) of 3.03 × 1024 molecules of carbon dioxide molecules? A) 221 B) 0.114 C) 1.33 D) 44.01 E) none of the above

221

How many moles of Cu are in 1.48 × 1025 Cu atoms? A) 0.0408 B) 24.6 C) 1.54 × 1025 D) 6.022 × 1023 E) none of the above

24.6

What is the mass percent of oxygen in sodium oxide? A) 37.1 B) 25.8 C) 74.2 D) 62.0 E) none of the above

25.8

What is the mass percent of carbon in oxalic acid, H2C2O4? A) 2.24 B) 13.3 C) 26.7 D) 34.5 E) none of the above

26.7

When the equation, ___N2 + ___H2 → ___NH3 is balanced, the coefficient of hydrogen is: A) 1 B) 2 C) 3 D) 4 E) none of the above

3

One half of a mole of atoms would contain how many atoms? A) 0.5 B) 3.011 × 1023 C) 6.022 × 1023 D) 6.022 × 1011.5 E) none of the above

3.011 x 1023

How many atoms are in 15.6 grams of silicon? A) 2.64 × 1026 B) 3.34 × 1023 C) 0.555 D) 438 E) none of the above

3.34

How many atoms are in 5.80 moles of He? A) 6.02 × 1023 B) 1.03 × 1023 C) 4.00 D) 3.49 × 1024 E) none of the above

3.49 x 1024

How many moles of carbon are in 3.5 moles of calcium carbonate? A) 10.5 B) 3.5 C) 7 D) 100.09 E) none of the above

3.5

How many moles of iron are contained in 1.75 kg of iron? A) 3.13 × 10-2 B) 3.13 × 10-4 C) 31.3 D) 3.13 × 104 E) none of the above

31.3

One mole of oxygen gas has a mass of ________ g. A) 16.0 B) 32.0 C) 6.022 × 1023 D) 8 E) none of the above

32.0

What is the molar mass of aluminum sulfate? A) 123.0 g/mol B) 278.0 g/mol C) 306.2 g/mol D) 315.2 g/mol E) 342.2 g/mol

342.2 g/mol

What is the mass (in grams) of 1.95 moles of water ? A) 18.02 B) 9.24 C) 35.1 D) 6.022 × 10 23 E) none of the above

35.1

What is the mass in grams of 5.40 moles of lithium? A) 6.94 B) 37.5 C) 1.29 D) 3.25 × 1024 E) none of the above

37.5

What is the mass percent of Na in sodium chloride? A) 58.4 B) 60.7 C) 39.3 D) 47.5 E) none of the above

39.3

What is the mass of 0.560 moles of chlorine gas? A) 19.9 B) 63.3 C) 127 D) 39.7 E) none of the above

39.7

) If you have 2.41 x 1024 atoms of copper, how many moles of copper do you have? A) 0.250 B) 4.00 C) 0.600 D) 3.00 E) none of the above

4

One mole of potassium sulfate contains: A) 4 moles of oxygen. B) 2 moles of sulfur. C) 1 mole of potassium. D) 3 moles of potassium. E) none of the above

4 moles of oxygen

A 500. gram iron ore sample was determined to contain 242 grams of iron. What is the mass percent of iron in the ore? A) 93.7 B) 48.4 C) 51.6 D) 32.6 E) none of the above

48.4

What is the value of n when the empirical formula is C3H5 and the molecular mass is 205.4g/mol? A) 0.02 B) 5 C) 10 D) 140 E) none of the above

5

How many moles of potassium are in 156.4 g? A) 39.10 B) 4.000 C) 0.2500 D) 5.050 E) none of the above

4.000

How many molecules of nitrogen monoxide are in a 22.5 gram sample? A) 5.86 × 1023 B) 7.33 × 1023 C) 4.51 × 1023 D) 4.06 × 1023 E) none of the above

4.51 x 1023

If 3.011 × molecules have a mass of 20.04 grams, what is the molar mass of this substance? A) 40.08 g/mol B) 10.02 g/mol C) 20.04 g/mol D) 6.658 × g/mol E) none of the above

40.08 g/mol

The mass of one mole of carbon dioxide is ________ g. A) 28.01 B) 384.4 C) 32.00 D) 44.01 E) none of the above

44.01

How many molecules of sulfur trioxide are in 78.0 grams? A) 5.87 × 1023 B) 7.33 × 1023 C) 3.76 × 1027 D) 0.974 E) none of the above

5.87 x 1023

Bauxite is an ore that contains the element aluminum. If you obtained 108 grams of aluminum from an ore sample that initially weighed 204 grams, what is the mass percent of aluminum in this bauxite ore? A) 52.9 B) 15.6 C) 0.53 D) 47.1 E) none of the above

52.9

What is the correct value for Avogadro's number? A) 6.022 × 1023 B) 6.022 × 1033 C) 6.023 × 1022 D) 6.022 × 102.3 E) none of the above

6.022 x 1023

A 15.5 gram sample of diphosphorous pentoxide contains how many grams of phosphorous? A) 3.38 B) 1.69 C) 6.76 D) 13.5 E) none of the above

6.76

When the equation, ___O2 + ___C5H12 → ___CO2 + ___H2O is balanced, the coefficient: of O2 is: A) 3 B) 4 C) 5 D) 8 E) none of the above

8

One mole of (NH4)2HPO4 contains how many moles of hydrogen atoms? A) 4 B) 2 C) 8 D) 9 E) none of the above

9

Which of the following contains 9.02 × 1023 atoms? A) 4.00 g H2 B) 9.00 g H2O C) 28.0 g N2 D) 32.0 g O2 E) none of the above

9.00 g H20

Calculate the molar mass of ammonium carbonate. A) 78.05 g/mol B) 88.05 g/mol C) 96.09 g/mol D) 112.09 g/mol E) none of the above

96.09 g/mol

What is the mass percent of chlorine in hydrochloric acid? A) 2.8 B) 35.5 C) 97.2 D) 70.1 E) none of the above

97.2

In writing the chemical equation for a precipitation reaction, what abbreviation of the physical state must appear with one of the products? A) (s) B) (g) C) (l) D) (w) E) none of the above

A) (s)

Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which compound would not form ions in the complete ionic equation? A) PbI2 B) KNO3 C) Pb(NO3)2 D) KI E) All compounds form ions in the complete ionic equation.

A) PbI2

The compound sodium sulfate is soluble in water. When this compound dissolves in water, which ion listed below would be present in solution? A) SO42- B) S2- C) O2- D) Na22+ E) none of the above

A) SO42-

What type of reaction is the generic equation a+b=ab A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above

A) synthesis/combination

60) A redox reaction has occurred ________. A) when a substance reacts with elemental oxygen B) when an alkali metal reacts with an alkaline earth metal C) when one substance transfers protons to another D) when one substance forms a solid E) when all of the above occur

A) when a substance reacts with elemental oxygen

A 7.96 gram sample of silver reacts with oxygen to form 8.55 gram of the metal oxide. What is the formula of the oxide? A) AgO B) AgO2 C) Ag2O D) Ag3O E) none of the above

Ag20

One mole of ammonium nitrite contains: A) 2 moles of nitrogen atoms. B) 4 moles of hydrogen atoms. C) 2 moles of oxygen atoms. D) All of A, B, and C. E) None of A, B, and C.

All of A, B, and C

Which of the following statements about empirical formulas is incorrect? A) An empirical formula represents a molecule. B) An empirical formula gives the smallest whole number ratio of each type of atom in a molecule. C) An empirical formula must be multiplied by an integer to obtain the molecular formula. D) The molecular formula can be the same as the empirical formula in some situations. E) All statements are correct

An empirical formula represents a molecule

Methane gas (CH4), on complete combustion in air, produces: 1. CO2 2. H2 3. H2O A) 1 and 2 only B) 1 and 3 only C) 2 and 3 only D) All of 1 and 2 only E) None of

B) 1 and 3 only

If you had an aqueous mixture that contained Ag+, K+, and Pb2+ cations, how many different solids could precipitate if a chloride solution was added? A) 1 B) 2 C) 3 D) 4

B) 2

What are the coefficients for the following reaction when it is properly balanced? ___potassium iodide + ___lead (II) acetate → ___lead (II) iodide +___potassium acetate A) 2, 1, 1, 1 B) 2, 1, 1, 2 C) 3, 2, 2, 1 D) 1, 1, 2, 2 E) none of the above

B) 2, 1, 1, 2

You have 10.0 g each of Na, C, Pb, Cu and Ne. Which contains the largest number of moles? A) Na B) C C) Pb D) Cu E) Ne

C

16) What are the coefficients for the following reaction when it is properly balanced? ___nitrogen monoxide + ___carbon monoxide → ___nitrogen +___carbon dioxide A) 2, 1, 1, 2 B) 2, 2, 1, 2 C) 2, 2, 2, 1 D) 1, 1, 2, 2

B) 2, 2, 1, 2

Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which ion(s) would NOT be present in the net ionic equation? A) Pb2+, NO3- B) K+, NO3- C) K+, Pb2+ D) K+, I- E) All the above ions are in the net ionic equation.

B) K+, NO3-

What type of reaction is the generic equation ab=a+b A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above

B) decomposition

18) When the equation __NO2 + __H2O + __O2 → __HNO3 is balanced, the coefficient of HNO3 is: A) 2 B) 3 C) 4 D) 5 E) none of the above

C) 4

17) When the equation __Ca3N2 + __H2O → __Ca(OH)2 + __NH3 is balanced, the coefficient of H2O is: A) 2 B) 3 C) 6 D) 12 E) none of the above

C) 6

What type of reaction is the generic equation A + BC → AC + B? A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above

C) single displacement

An unknown acid has a molar mass of 60.06 g/mol. Given the following percent composition, what is the molecular formula? . A) C3H4O3 B) CH2O C) C2H4O2 D) C6H12O6 E) none of the above

C2H4O2

Vitamin C is known chemically by the name ascorbic acid. Determine the empirical formula of ascorbic acid if it is composed of 40.92% carbon, 4.58% hydrogen, and 54.50% oxygen. A) CHO B) CH2O C) C2H3O2 D) C3H4O3 E) none of the above

C3H403

Which of the following is already in its empirical formula? A) C22H34O10 B) C6H6 C) C6H12O3 D) C5H12O2 E) none of the above

C5H1202

A compound has a molar mass of 180.18 g/mol. Given the following percent composition, calculate the molecular formula: 39.99% C, 6.73% H, 53.28% O. A) CH3O2 B) CH2O C) C3H6O3 D) C6H12O6 E) none of the above

C6H12O6

Which of the following statements about balancing reactions is FALSE? A) If there is no coefficient or subscript, a one is implied. B) When coefficients are added the type of compounds is changed in the chemical reaction. C) Subscripts are multiplied by the coefficients to determine the number of atoms in a compound. D) Coefficients are added to compounds to ensure both sides of the reaction have equal numbers of each atom. E) All of the above statements are true.

Coefficients are added to compounds to ensure both sides of the reaction have equal numbers of each atom

A chromium oxide compound contains 104.0 grams of chromium and 48.0 grams of oxygen. What is the most likely empirical formula of this compound? A) CrO B) CrO2 C) CrO3 D) Cr2O3 E) Cr3O2

Cr203

What are the coefficients for the following reaction when it is properly balanced? ___nitric acid + ___sodium hydroxide → ___sodium nitrate + ___water A) 2, 1, 1, 1 B) 2, 3, 2, 2 C) 5, 2, 2, 1 D) 1, 1, 1, 1 E) none of the above

D) 1, 1, 1, 1

20) Sodium metal reacts with water to form aqueous sodium hydroxide and hydrogen gas. Which equation below best describes the balanced equation for this reaction? A) Na + H2O → NaOH (aq) + H (g) B) S + H2O → SOH (aq) + H (g) C) Na + H2O → NaOH (aq) + H2 (g) D) 2Na + 2H2O → 2NaOH (aq) + H2 (g) E) 2Na + H2O → Na2OH (aq) + H (g) Answer: D

D) 2Na + 2H2O → 2NaOH (aq) + H2 (g)

19) Which of the following equations is NOT balanced properly? A) 2Cr + 6HCl → 2CrCl3 + 3H2 B) 2NaHCO3 → Na2CO3 + CO2 + H2O C) Cr2(SO4)3 + 6KOH → 2Cr(OH)3 + 3 K2SO4 D) 4NH3 + 14O2 → 4NO2 + 6H2O E) none of the above

D) 4NH3 + 14O2 → 4NO2 + 6H2O

Identify the oxidation-reduction reactions among the following: 1. Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s) 2. 2 Na(s) + Cl2(aq) → 2NaCl(s) 3. 2 Mg(s) + O2(g) → 2 MgO A) 1 and 2 only B) 1 and 3 only C) 2 and 3 only D) All of 1, 2, and 3 E) None of 1, 2, and 3

D) All of 1, 2, and 3

When a solution of MgCl2 and one of AgNO3 are mixed, the net ionic equation is: A) Mg2+(aq) + 2Cl-(aq) + 2Ag+(aq) + 2NO3- (aq) → Mg2+(aq) + 2NO3-aq) + 2AgCl(s) B) Mg2+(aq) + 2Cl-(aq) + 2Ag+(aq) + 2NO3- (aq) → Mg(NO3)2 (aq) + 2 AgCl(s) C) Mg2+(aq) + 2NO3-(aq) → Mg(NO3)2(aq) D) Cl-(aq) + Ag+(aq) → AgCl(s) E) none of the above

D) Cl-(aq) + Ag+(aq) → AgCl(s)

Which of the following would NOT be a product from mixing hydrochloric acid with a solution of sodium sulfite? A) H2O (l) B) SO2 (g) C) NaCl (aq) D) H2 (g) E) none of the above

D) H2 (g)

What is the molecular equation for the reaction of hydrochloric acid with potassium hydroxide? A) H2Cl + 2KOH → H2O +2KCl B) 2HCl + K(OH)2 → 2H2O + KCl2 C) H+ + OH- → H2O D) HCl + KOH → H2O + KCl E) none of the above

D) HCl + KOH → H2O + KC

Several grams of sodium chloride are stirred into a glass of water and are no longer visible to the eye. Which of the following statements is FALSE? A) The sodium chloride solid has dissociated into its component ions. B) An aqueous solution has been prepared. C) No precipitate has formed. D) Sodium chloride is insoluble in water. E) All of the statements are true

D) Sodium chloride is insoluble in water.

) When solid NaCl is stirred into water, which of the following is NOT true? A) Individual sodium and chloride ions are present. B) The solution will conduct electricity. C) The solution will taste salty. D) The NaCl will fail to dissociate. E) none of the above

D) The NaCl will fail to dissociate.

Which of the following compounds is SOLUBLE? A) aluminum hydroxide B) aluminum sulfide C) aluminum carbonate D) aluminum sulfate E) none of the above

D) aluminum sulfate

22) Which of the following compounds is INSOLUBLE? A) potassium acetate B) lithium carbonate C) magnesium bromide D) aluminum sulfide E) none of the above

D) aluminum sulfide

A precipitate is expected to be formed when an aqueous solution of sodium sulfate is added to an aqueous solution of: A) iron(III) chloride. B) potassium chloride. C) magnesium chloride. D) barium chloride. E) none of the above

D) barium chloride.

What type of reaction is the generic equation ab+cd=ad+cb A) synthesis/combination B) decomposition C) single displacement D) double-displacement E) none of the above

D) double-displacement

What type of a reaction occurs when a hydrochloric acid solution is mixed with a sodium bicarbonate solution? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction

D) gas evolution

21) An aqueous solution is: A) any liquid with another compound dissolved in it. B) an ionic compound with water dissolved in it. C) water with a molecular compound dissolved in it. D) water with another compound dissolved in it. E) none of the above

D) water with another compound dissolved in it.

Which of the following statements about writing molecular, complete and net ionic equations is FALSE? A) A molecular equation is a chemical equation showing the complete, neutral formulas for every compound in a reaction. B) A complete ionic equation is a chemical equation showing all of the species as they are actually present in solution. C) A net ionic equation is an equation showing only the species that actually participate in the reaction. D) A spectator ion remains unchanged in the reaction and appears on both sides of the equation. E) All of the statements are true.

E) All of the statements are true

Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which ion would NOT be present in the complete ionic equation? A) Pb2+ B) K+ C) NO3- D) I- E) All the above ions are in the complete ionic equation.

E) All the above ions are in the complete ionic equation.

26) All of the following compounds are soluble in water EXCEPT: A) NaCl. B) CaCl2. C) FeCl3. D) NH4Cl. E) PbCl2

E) PbCl2

What must be supplied for a decomposition reaction to happen? A) energy B) heat C) electrical current D) light E) any of the above

E) any of the above

) What type of a reaction occurs when a potassium nitrate solution is mixed with a barium acetate solution? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction

E) no reaction

An iron chloride compound contains 55.85 grams of iron and 106.5 grams of chlorine. What is the most likely empirical formula for this compound? A) FeCl B) FeCl2 C) Fe2Cl D) FeCl3 E) Fe3Cl

FeCl3

A compound composed of only hydrogen and oxygen is 5.94% hydrogen by mass. The molar mass of this compound is 34.02 g/mol. What is the compound's molecular formula? A) 34.02 B) H2O2 C) HO D) H6O E) none of the above

H202

The empirical formula of a compound: A) describes the mass relationships in a molecule. B) is the same as the molecular formula. C) indicates the structure of the molecule. D) indicates the simplest ratio of atoms in the compound. E) none of the above

Indicates the simplest ratio of atoms in the compound

Determine the empirical formula of a compound containing 83% potassium and 17.0% oxygen. A) KO B) KO2 C) K2O3 D) K2O E) none of the above

K20

Determine the empirical formula of a compound containing 60.3% magnesium and 39.7% oxygen. A) MgO B) MgO2 C) Mg2O3 D) Mg2O E) none of the above

MgO

Which of the following compounds has the highest mass percent of "O"? A) MnO B) MnO2 C) Mn2O3 D) Mn3O2 E) none of the above

Mn02

What is the molecular formula of a compound given the molar mass of the compound is 30.04 gram and the empirical formula is NH? A) NH B) N2H2 C) N2H6 D) N4H4 E) none of the above

N2H2

If 2.01 × atoms of an element from Group IA of the periodic table has a mass of 7.675 grams, this element is most likely: A) Li. B) Na. C) K. D) Rb. E) Cs.

Na

When water is heated, bubbles form in the water. Is this evidence of a chemical reaction? Why? A) No, boiling water is a physical change. B) Yes, the formation of a gas is evidence of a chemical reaction. C) No, the formation of gas bubbles is a secondary chemical reaction which is ignored. D) Yes, the formation of a gas is proof a new compound has been made. E) none of the above

No, boiling water is a physical change

Which of the following statements about the mole is FALSE? A) One mole of atoms makes up an amount of atoms that can be seen with the naked eye. B) A mole of a monatomic element corresponds to one Avogadro's number of atoms. C) One mole of a monatomic element has a mass equal to its atomic mass expressed in grams. D) One mole of water contains 1/2 mole of oxygen atoms. E) none of the above

One mole of water contains 1/2 mole of oxygen atoms

You have 10.0 g each of Na, C, Pb, Cu and Ne. Which contains the smallest number of moles? A) Na B) C C) Pb D) Cu E) Ne

Pb

In comparing a balloon containing 25 grams of helium to a balloon containing 25 grams of neon, which one of the following statements is TRUE? A) Each balloon has an equal number of atoms. B) The helium balloon has more atoms. C) The neon balloon has more atoms. D) This scenario cannot happen because gases have no mass. E) none of the above

The helium balloon has more atoms

In comparing 1 mole of carbon atoms to one mole of magnesium atoms, which statement is TRUE? A) The mass of 1 mole of carbon is greater than the mass of 1 mole of magnesium. B) The mass of 1 mole of magnesium is greater than the mass of 1 mole of carbon. C) The mass of 1 mole of carbon is the same as the mass of 1 mole of magnesium. D) There are more atoms in 1 mole of magnesium than in 1 mole of carbon. E) none of the above

The mass of 1 mole of magnesium is greater than the mass of 1 mole of carbon

The simplest formula for hydrogen peroxide is HO. To determine its molecular formula, it is necessary to know: A) the properties of hydrogen peroxide. B) the density of hydrogen peroxide. C) the molar mass of hydrogen peroxide. D) the number of moles of hydrogen peroxide in 1.00 g of the substance. E) none of the above

The molar mass of hydrogen peroxide

Which of the following is NOT typically a sign of a chemical reaction? A) absorbing heat when chemicals are contacted with each other B) emission of heat when chemicals are contacted with each other C) emission of light when chemicals are contacted with each other D) absorbing light when chemicals are contacted with each other E) All of the above are signs of a chemical reaction.

absorbing the light when chemicals are contacted with earch other

Which of the following is NOT evidence that a chemical reaction has occurred? A) color change when chemicals are contacted with each other B) solid formation when chemicals are contacted with each other C) gas formation when chemicals are contacted with each other D) emission of light when chemicals are contact with each other E) All of the above are evidence of a chemical reaction.

all of the above

A reaction in which a substance reacts with oxygen, emitting heat and forming oxygen-containing compounds is an example of a(n): A) acid-base reaction. B) combustion reaction. C) precipitation reaction. D) gas evolution reaction. E) none of the above

combustion reaction

The chemical formula CH2O can be classified as: A) molecular only. B) empirical only. C) empirical, possibly molecular. D) not enough information E) none of the above

empirical, possibly molecular

A reaction which forms a gaseous product is an example of a(n)________. A) oxidation-reduction reaction B) combustion reaction C) precipitation reaction D) gas evolution reaction E) none of the above

gas evolution reaction

What is the molecular formula of a compound given the molar mass of the compound is 186.5g and the empirical formula is C2H7? A) C4H14 B) C3H21 C) C2H7 D) C2H14 E) none of the above

none of the above

What would the empirical formula be for the molecular compound C6H9O4? A) C2H3O2 B) CH3O2 C) C3H6O2 D) C3H9O4 E) none of the above

none of the above

What type of a reaction occurs when potassium metal reacts with fluorine gas? A) precipitation B) acid-base neutralization C) oxidation-reduction D) gas evolution E) no reaction

oxidation-reduction

24) Which of the following compounds is SOLUBLE? A) copper carbonate B) calcium carbonate C) potassium carbonate D) strontium carbonate E) none of the above

potassium carbonate

A reaction which forms a solid product is an example of a(n): A) oxidation-reduction reaction. B) combustion reaction. C) precipitation reaction. D) gas evolution reaction. E) none of the above

precipitation reaction

Before a chemical equation can be written, one must know: A) the atomic mass of all the elements involved. B) the molar mass of all the compounds. C) the symbols and formulas of all reactants and products. D) the number of moles of all reactants and products. E) none of the above.

the symbols and formulas of all reactants and products