Chapter 3 3 Dinitrogen monoxide gas decomposes to form nitrogen

28) Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of

oxygen are formed when 20.0 g of dinitrogen monoxide decomposes?

A) 0.138 g

B) 7.27 g

C) 14.5 g

D) 29.1 g

29) Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of

nitrogen are formed when 30.00 g of dinitrogen monoxide decomposes?

A) 9.545 g

B) 19.09 g

C) 30.00 g

D) 60.00 g

30) Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of

nitrogen are formed when 5.54 g of dintrogen monoxide decomposes?

A) 4.35

B) 17.41

C) 3.53

D) 7.06

37

31) If the density of ethanol, C2H5OH, is 0.789 g/mL. How many milliliters of ethanol are needed to

produce 10.0 g of CO2 according to the following chemical equation?

C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l)

A) 4.13 mL

B) 6.63 mL

C) 13.3 mL

D) 26.5 mL

32) 1.00 mole of O2 contains the same number of molecules as

A) 0.667 mole of O3.

B) 1.00 mole of CH3CO2CH2Cl.

C) 2.00 mole of CH3CH2OCH2Br.

D) All of these

33) Which represents one formula unit?

A) One Cu

B) One F2

C) One NaH

D) All of these

34) Identify one mole of a substance.

A) 32.0 grams of H2

B) 52.0 grams of Cr

C) 8.0 grams of LiH

D) All of these

35) What is the number of moles of 5.00 × 1022 molecules of NaBr?

A) 0.037 moles

B) 1.0 moles

C) 0.083 moles

D) 1.2046 moles

36) How many chloride ions are in 1.50 mol of aluminum chloride?

A) 2.00 chloride ions

B) 2.009.023 chloride ions

C) 9.023 × 1023 chloride ions

D) 2.71 × 1024 chloride ions

37) When 14.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced. Using

the following balanced equation, calculate the percent yield for the reaction?

Ca(s) + 2 H2O(l) → Ca(OH)2(aq) + H2(g)

A) 9.67%

B) 19.3%

C) 35.7%

D) 66.0%

38) When 12.00 g of calcium metal is reacted with water, 12.00 g of calcium hydroxide is produced. Using

the following balanced equation, calculate the percent yield for the reaction?

Ca(s) + 2 H2O(l) → Ca(OH)2(aq) + H2(g)

A) 27.02%

B) 54.05%

C) 100.0%

D) 30.00%

39) If the percent yield for the following reaction is 65.0%, how many grams of KClO3 are needed to

produce 42.0 g of O2?

2 KClO3(s) → 2 KCl(s) + 3 O2(g)

A) 69.7 g

B) 107 g

C) 165 g

D) 371 g

40) If the percent yield for the following reaction is 80.0%, how many grams of KClO3 are needed to

produce 42.0 g of O2?

2 KClO3(s) → 2 KCl(s) + 3 O2(g)

A) 10.5 g

B) 62.5 g

C) 134 g

D) 63.0 g

41) If the percent yield for the following reaction is 75.0%, and 35.0 g of NO2 are consumed in the

reaction, how many grams of nitric acid, HNO3(aq) are produced?

3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

A) 24.0 g

B) 31.9 g

C) 42.6 g

D) 53.9 g

42) Hydrazine, N2H4, once used as a rocket propellant, reacts with oxygen in the following equation.

N2H4(g) + O2(g) → N2(g) + 2 H2O(g)

The reaction, at 50% yield, produces 4.0 moles of N2. What was the mass of hydrazine used? Assume

that O2 is in excess.

A) 32.0 g

B) 260 g

C) 64 g

D) 0.063 g

43) Consider the following balanced reaction.

4A + 2B → 2C + D

8.0 moles of A and 30. moles of B react to form 2.5 moles of C. What is the percent yield of this reaction?

A) 10%

B) 62.5%

C) 83%

D) 100%

44) 10 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical

equation shown below. Which one of the following statements is false?

N2(g) + 3 H2(g) → 2 NH3(g)

A) 2.8 g of hydrogen are left over.

B) Hydrogen is the excess reactant.

C) Nitrogen is the limiting reactant.

D) The theoretical yield of ammonia is 15 g.

45) 9.0 g of iron is reacted with 9.0 g of water according to the chemical equation shown below. Which

one of the following statements is false?

3 Fe(s) + 4 H2O(l) → Fe3O4(s) + 4 H2(g)

A) 12.4 g of Fe3O4 are produced.

B) 5.13 g of H2O are left over.

C) Mass is conserved in this reaction.

D) Water is the limiting reactant.

46) Which substance is the limiting reactant when 8.0 g of sulfur reacts with 12 g of oxygen and 16 g of

sodium hydroxide according to the following chemical equation?

2 S(s) + 3 O2(g) + 4 NaOH(aq) → 2 Na2SO4(aq) + 2 H2O(l)

A) S(s)

B) O2(g)

C) NaOH(aq)

D) None of these substances is the limiting reactant.

47) Which substance is the limiting reactant when 16.0 g of sulfur reacts with 10.0 g of oxygen and 12.0 g

of sodium hydroxide according to the following chemical equation?

2 S(s) + 3 O2(g) + 4 NaOH(aq) → 2 Na2SO4(aq) + 2 H2O(l)

A) S(s)

B) O2(g)

C) NaOH (aq)

D) Na2SO4(aq)

48) When 5.00 × 1022 molecules of ammonia react with 4.00 × 1022 molecules of oxygen according to the

chemical equation shown below, how many grams of nitrogen gas are produced?

4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g)

A) 1.16 g

B) 1.24 g

C) 2.79 g

D) 4.65 g

49) When 1.00 × 1022 molecules of ammonia react with 7.00 × 1022 molecules of oxygen according to the

chemical equation shown below, how many grams of nitrogen gas are produced?

4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g)

A) 0.232 g

B) 2.17 g

C) 0.464 g

D) 1.86 g

50) When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How

many grams of silver chloride are formed when 10.8 g of silver nitrate reacts with 15.0 g of barium

chloride?

A) 9.11 g

B) 9.40 g

C) 12.9 g

D) 18.8 g

51) Balance the chemical equation given below, and calculate the volume of nitrogen monoxide gas

produced when 8.00 g of ammonia is reacted with 9.00 g of oxygen at 25°C? The density of nitrogen

monoxide at 25°C is 1.23 g/L.

________ NH3(g) + ________ O2(g) → ________ NO(g) + ________ H2O(l)

A) 5.49 L

B) 8.31 L

C) 11.5 L

D) 17.3 L

52) Which one of the following compounds contains the smallest percent oxygen by mass?

A) CO2

B) N2O4

C) P10O5

D) C9H20O

44

53) Which one of the following contains 52% carbon by mass?

A) C2H2

B) CH4

C) CH3OCH3

D) CO2

54) What is the empirical formula of a substance that contains 2.64 g of C, 0.444 g of H, and 3.52 g of O?

A) CH2O

B) C2H4O2

C) C2H4O3

D) C3H4O4

55) What is the empirical formula for perfluoropropane if the compound contains 81% fluorine and 19%

carbon by mass?

A) CF3

B) C2F4

C) C3F8

D) C6F10

56) What is the empirical formula of a substance that contains 12.0 g of C, 2.00 g of H, and 5.33 g of O?

A) C3H6O

B) C15H30O5

C) C3H5O3

D) C3H4O4

57) Which one of the following is not an empirical formula?

45

A) CHO

B) CH2O

C) C2H4O

D) C2H2O4

58) Which one of the following is not an empirical formula?

A) CHO

B) CH2O

C) C3H6O

D) C8H16O4

59) Which one of the following is an empirical formula?

A) C2F6

B) H2SO2

C) C2H4O2

D) P4O10

60) Combustion analysis of an unknown compound containing only carbon and hydrogen produced

1.1385 g of CO2 and 0.5805 g of H2O. What is the empirical formula of the compound?

A) CH2

B) C2H5

C) C4H10

D) C5H2

61) Combustion analysis of 0.150 g of an unknown compound containing carbon, hydrogen, and oxygen

produced 0.2607 g of CO2 and 0.1418 g of H2O. What is the empirical formula of the compound?

A) C2H5O

B) C2H5O2

C) C2H10O3

D) C3H8O2

3.3 Short Answer Questions

1) A balanced equation has the same numbers and kinds of ________ on both sides of the reaction arrow.

2) When the reaction C4H10 + O2 → CO2 + H2O is balanced using the smallest whole number

coefficients, the coefficient in front of O2 is ________.

3) When the reaction C3H8 + O2 → CO2 + H2O is balanced, the total number of oxygen atoms in the

balanced equation is ________.

4) The fundamental SI unit for measuring matter is the ________.

5) To the nearest whole number, the molar mass of Cu(NO3)2 is ________ g/mol.

6) The number of grams in 0.250mol of urea, (NH2)2CO, is ________.

7) How many moles are in 7.8 g of acetamide, CH3CONH2?

8) The balanced equation for the gaseous state oxidation of ammonia is shown below.

4 NH3 + 5 O2 → 4 NO + 6 H2O

How many moles of O2 are required to react with 1.2 mole of NH3?

9) The balanced equation for the reaction of acetylene, C2H2, and oxygen in an acetylene torch is

2 C2H2 + 5 O2 → 4 CO2 + 2 H2O.

In this reaction the number of grams of oxygen required to react with 0.13 g of acetylene is ________.

10) Ozone is unstable, decomposing to oxygen, as shown in the balanced equation

2 O3 → 3 O2.

In this reaction, how many grams of oxygen can be formed from the decomposition of 96 grams of ozone?

11) Ozone reacts with iodide ion as shown in the balanced equation below.

O3 + 2 I– + H2O → O2 + I2 + 2 OH–

In this reaction, how many grams of oxygen can be formed from the reaction of 126 grams of ozone?

12) Tablets of ascorbic acid, or Vitamin C, C6H8O6, are taken as a dietary supplement. If a typical tablet

contains 500 mg, how many atoms of carbon (C) are in a tablet?

13) The balanced equation for the decomposition of water is shown below.

2 H2O → 2 H2 + O2

If 0.72 g of water react completely in this reaction, what is the theoretical yield of H2?

14) Oxygen can be produced from the catalytic decomposition of KClO3 as shown in the balanced

equation below.

2 KClO3 → 2 KCl + 3 O2

What is the percent yield if 3.20 grams of oxygen are formed from the reaction of 12.3 grams of KClO3?

15) If 2.7 g of H2 react with 2.7 g of F2 in the reaction shown below, what is the limiting reactant?

H2 + F2 → 2 HF

16) When carbon dioxide dissolves in water, H+ is formed, which makes the solution acidic, as shown in

the balanced equation below.

CO2 + H2O → HCO3– + H+

What is the percent yield if 0.0088 g of CO2 reacts with 900 g of H2O to form 0.000108 g of H+?

17) Hydrazine, N2H4, is used as a rocket fuel. In the reaction below, if 80.1 g of N2H4 and 92.0 g of N2O4

are allowed to react, which is the limiting reactant, and how many grams of excess reactant remain at the

end of the reaction?

2 N2H4 + N2O4 → 3 N2 + 4 H2O

18) What is the empirical formula of benzene, C6H6?

19) The empirical formula of a compound that contains 82.66% carbon and 17.34% hydrogen is ________.

20) Analysis of a 1.000-g sample of the oral hypoglycemic agent metforminTM yielded 0.3720 g of carbon,

0.0858 g of hydrogen, and 0.5422 g of nitrogen. MetforminTM has a molar mass of 129.16 g/mol. What is

the molecular formula of MetforminTM?