Ch6 Quantities In Chemical Reactions Test Bank Docx

Introduction to Chemistry, 5e (Bauer)

Chapter 6 Quantities in Chemical Reactions

1) When one molecule of propane, C3H8, burns in a gas grill, it combines with five oxygen molecules to form three CO2 molecules and four H2O molecules. Select the statement below that is incorrect in regard to this reaction.

A) The balanced equation for the reaction is C3H8 + 5O2 → 3CO2 + 4H2O.

B) If 5 propane molecules react, 15 CO2 molecules should form.

C) If 5 propane molecules react, 25 O2 molecules must also react.

D) If 15 O2 molecules react, 9 H2O molecules should form.

E) If 12 CO2 molecules are formed, then 4 propane molecules must have reacted.

2) When ethanol, C2H5OH, a component in some gasoline mixtures, is burned in air, one molecule of ethanol combines with three oxygen molecules to form two CO2 molecules and three H2O molecules. Select the statement below that is incorrect in regard to this reaction.

A) The balanced equation for the reaction is C2H5OH + 3O2 → 2CO2 + 3H2O.

B) If 4 ethanol molecules react, 8 CO2 molecules should form.

C) If 12 H2O molecules are formed, then 9 O2 molecules must have reacted.

D) If 15 ethanol molecules react, then 45 oxygen molecules must also react.

E) If 12 CO2 molecules are formed, then 18 H2O molecules should also form.

3) When acetylene, C2H2, a fuel used in welding, is burned in air, two molecules of acetylene combine with five oxygen molecules to form four CO2 molecules and two H2O molecules. Select the statement below that is incorrect in regard to this reaction.

A) The balanced equation for the reaction is 2C2H2 + 5O2 → 4CO2 + 2H2O.

B) If 8 acetylene molecules react, 12 CO2 molecules should form.

C) If 12 H2O molecules are formed, then 30 O2 molecules must have reacted.

D) If 12 CO2 molecules are formed, then 6 H2O molecules should also form.

E) If 24 ethanol molecules react, then 60 oxygen molecules must also react

4) All of the following may change during a chemical reaction except

A) the total number of atoms in the system.

B) the temperature of the system.

C) the color of the system.

D) the total number of molecules in the system.

E) the physical state of the system.

5) When sodium sulfate, Na2SO4, dissolves in water, the ions that are formed for each formula unit that dissolves are:

A) Na22+(aq) + SO42−(aq)

B) 2Na2+(aq) + SO42−(aq)

C) 2Na+(aq) + SO42−(aq)

D) Na22+(aq) + S(s) + O42−(aq)

E) Na22+(aq) + S2−(aq) + 4O2−(aq)

6) When potassium carbonate, K2CO3, dissolves in water, the ions that are formed for each formula unit that dissolves are:

A) K22+(aq) + CO32−(aq)

B) 2K2+(aq) + CO32−(aq)

C) 2K+(aq) + CO32−(aq)

D) 2K+(aq) + C(s) + O32−(aq)

E) K22+(aq) + C4+(aq) + 3O2−(aq)

7) When ammonium carbonate, (NH4)2CO3, dissolves in water, the ions that are formed for each formula unit that dissolves are:

A) (NH4)22+(aq) + CO32−(aq)

B) 2NH4+(aq) + CO32−(aq)

C) 2N3−(aq) + 4H+(aq) + CO32−(aq)

D) 2N3−(aq) + 4H+(aq) + C(s) + O32−(aq)

E) 2N3−(aq) + 4H+(aq) + C4+(aq)+ 3O2−(aq)

8) Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

A) 4A + 8B → 12AB

B) 2A2 + 4B2 → 4A2B

C) 2A2 + 4B2 → 4AB2

D) A2 + B2 → AB2

E) A2 + 2B2 → 2AB2

9) Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

A) 16H + 10O → 16H + 10O

B) 16H + 10O → 8H2O + O2

C) 8H2 + 5O2 → 8H2O + O2

D) 2H2 + O2 → 2H2O

E) 4H2 + 2O2 → 4H2O

10) Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

A) 12N + 12H → 12NH

B) 6N2 + 6H2 → 4NH3

C) 6N2 + 6H2 → 4NH3 + 4N2

D) 12N + 12H → 4NH3 + 8N

E) N2 + 3H2 → 2NH3

11) When the mixture of molecules shown in the molecular-level image undergoes complete reaction, all of these molecules are converted to products. Which of the following reactions could this represent?

A) N2 + O2 → 2NO

B) N2 + 2Cl2 → N2Cl4

C) N2 + 2O2 → 2NO2

D) N2 + 3H2 → 2NH3

E) N2 + 3O2 → 2NO3

12) When the mixture of molecules shown in the molecular-level image undergoes complete reaction, all of these molecules are converted to products. Which of the following reactions could this represent?

A) 2N2 + 3O2 → 2N2O3

B) N2 + 2Cl2 → N2Cl4

C) O2 + 2H2 → 2H2O

D) N2 + 3Cl2 → 2NCl3

E) 3N2 + 2H2 → 3N2H4

13) When mixed, solutions of aluminum nitrate, Al(NO3)3, and ammonium carbonate, (NH4)2CO3, will form a precipitate of aluminum carbonate, Al2(CO3)3. The balanced equation is 2Al(NO3)3(aq) + 3(NH4)2CO3(aq) → Al2(CO3)3 (s) + 6NH4NO3(aq) Which of the following statements regarding this reaction is incorrect?

A) 2 moles of Al(NO3)3 will react with 3 moles of (NH4)2CO3.

B) If 6 moles of (NH4)2CO3 react with sufficient Al(NO3)3, 2 moles of Al2(CO3)3 should form.

C) If 0.5 mole of (NH4)2CO3 react with sufficient Al(NO3)3, 3 moles of Al2(CO3)3 should form.

D) If 1.5 moles of Al2(CO3)3 are formed, given sufficient starting materials, then 9 moles of NH4NO3 should also form.

E) 4 moles of Al(NO3)3 will react with 6 moles of (NH4)2CO3.

14) When mixed, solutions of silver nitrate, AgNO3, and sodium phosphate, Na3PO4, will form a precipitate of silver phosphate, Ag3PO4. The balanced equation is 3AgNO3(aq) + Na3PO4(aq) → Ag3PO4(s) + 3NaNO3(aq) Which of the following statements regarding this reaction is incorrect?

A) 6 moles of AgNO3 will react with 2 moles of Na3PO4.

B) 9 moles of AgNO3 should react to form 2 moles of Ag3PO4, given sufficient Na3PO4.

C) 1.5 moles of NaNO3 should form when 0.5 mole of Na3PO4 reacts with sufficient AgNO3.

D) 3 moles of Ag3PO4 should form when 3 moles of Na3PO4 react with sufficient AgNO3.

E) 2 moles of Na3PO4 will react with 6 moles of AgNO3.

15) When mixed, solutions of copper(II) nitrate, Cu(NO3)2, and sodium phosphate, Na3PO4, will form a precipitate of copper phosphate, Cu3(PO4)2. The balanced equation is 3Cu(NO3)2(aq) + 2Na3PO4(aq) → Cu3(PO4)2(s) + 6NaNO3(aq) Which of the following statements regarding this reaction is incorrect?

A) 8 moles of Na3PO4 will react with 12 moles of Cu(NO3)2.

B) 1 mole of NaNO3 should form when 0.5 mole of Cu(NO3)2 reacts with sufficient Na3PO4.

C) 12 moles of Cu3(PO4)2 should form when 36 moles of Cu(NO3)2 reacts with sufficient Na3PO4.

D) If 10 moles of Na3PO4 react with sufficient Cu(NO3)2, 4 moles of Cu3(PO4)2 should form.

E) If 5 moles of Cu3(PO4)2 are needed, it would require the combination of 15 moles of Cu(NO3)2 and 10 moles of Na3PO4.

16) Consider the reaction between hydrogen and oxygen gases to form water: 2H2(g) + O2(g) → 2H2O(l) Which of the following is not conserved in this reaction?

A) atoms

B) moles of atoms

C) moles of molecules

D) mass

17) Consider the reaction between sodium metal and chlorine gas to form sodium chloride: 2Na(s) + Cl2(g) → 2NaCl(s) Which of the following is not conserved in this reaction?

A) atoms

B) moles of atoms

C) moles of molecules

D) mass

18) Consider the reaction between acetylene, C2H2, and oxygen in a welding torch: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g) Which of the following is not conserved in this reaction?

A) atoms

B) moles of atoms

C) moles of molecules

D) mass

19) Which of the following equations is balanced?

A) P4(s) + 10O2(g) → P4O10(s)

B) ZnS(s) + 3O2(g) → ZnO(s) + 2SO2(g)

C) NH3(g) + O2(g) → NO2(g) + H2O(g)

D) 4KBrO3(s) → 3KBrO4(s) + KBr(s)

E) 2Na(s) + P(s) → Na3P(s)

20) Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) → P4O10(s) + 6H2O(g) If 9.2 moles of phosphine react with sufficient oxygen, how many moles of P4O10 should form?

A) 4.0 moles

B) 9.2 moles

C) 37 moles

D) 2.3 moles

E) 6.0 moles

21) Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) → P4O10(s) + 6H2O(g) If you need to make 6.5 moles of P4O10, how many moles of PH3 is required for the reaction?

A) 6.5 moles

B) 13 moles

C) 26 moles

D) 3.2 moles

E) 1.6 moles

22) Given that 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 6.3 moles of NH3 react with sufficient oxygen, how many moles of NO should form?

A) 4.0 moles

B) 6.3 moles

C) 6.0 moles

D) 5.0 moles

E) 3.2 moles

23) Given that 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 8.2 moles of NH3 react with sufficient oxygen, how many moles of water should form?

A) 6.0 moles

B) 4.0 moles

C) 5.0 moles

D) 12 moles

E) 8.2 moles

24) Given that 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 4.5 moles of NH3 react with sufficient oxygen, how many moles of H2O should form?

A) 4.0

B) 4.5

C) 6.0

D) 6.8

E) 5.5

25) Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt): 2Na(s) + Cl2(g) → 2NaCl(s) If 3.6 moles of chlorine react with sufficient sodium, how many grams of sodium chloride should form?

A) 1.1 x 102 g

B) 2.1 x 102 g

C) 4.2 x 102 g

D) 0.13 g

E) 0.062 g

26) Consider the reaction between acetylene, C2H2, and oxygen in a welding torch: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g) If 5.4 moles of acetylene react with sufficient oxygen, how many grams of CO2 should form?

A) 2.4 x 102 g

B) 9.5 x 102 g

C) 4.8 x 102 g

D) 1.5 x 102 g

E) 0.49 g

27) Consider the reaction between hydrogen and oxygen gases to form water: 2H2(g) + O2(g) → 2H2O(l) If 8.5 moles of oxygen react with sufficient hydrogen, how many grams of water should form?

A) 0.94 g

B) 0.47 g

C) .76 g

D) 3.1 x 102 g

E) 1.5 x 102 g

28) Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) → P4O10(s) + 6H2O(g) If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P4O10 will be formed?

A) 125 g

B) 31.3 g

C) 5.00 x 102 g

D) 18.9 g

E) 75.7 g

29) Given the balanced equation 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 82.0 g of NH3 react with sufficient oxygen, how many grams of NO should form?

A) 145 g

B) 5.80 x 102 g

C) 46.5 g

D) 186 g

E) 11.6 g

30) Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt): 2Na(s) + Cl2(g) → 2NaCl(s) If 12.5 g of sodium react with sufficient chlorine, how many grams of sodium chloride should form?

A) 15.9 g

B) 31.8 g

C) 63.6 g

D) 4.92 g

E) 9.84 g

31) Given the balanced equation 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 32.5 g of NH3 react with sufficient oxygen, how many grams of H2O should form?

A) 51.6 g

B) 8.60 g

C) 34.4 g

D) 206.4 g

E) 878 g

32) When copper reacts with sulfur at high temperature, copper(I) sulfide is formed. 2Cu(s) + S(s) → Cu2S(s) If the mass of the Cu2S formed is 1.17 g, what mass of copper should have reacted?

A) 0.934 g

B) not enough information

C) 0.78 g

D) 2.34 g

E) 0.467 g

33) When magnesium is heated in air, it reacts with oxygen to form magnesium oxide: 2Mg(s) + O2(g) → 2MgO(s) If the mass of the magnesium solid increases by 0.335 g, what mass of magnesium metal should have reacted?

A) 0.882 g

B) 0.441 g

C) 0.509 g

D) 1.02 g

E) not enough information

34) Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt): 2Na(s) + Cl2(g) → 2NaCl(s) If the mass of the sodium solid increases by 0.500 g, what mass of sodium metal should have reacted?

A) 0.250 g

B) 0.500 g

C) 0.0811 g

D) 0.162 g

E) 0.324 g

35) When a 0.525 g piece of zinc is placed in a solution of copper(II) sulfate, copper metal and zinc sulfate are formed. Balance the equation for the reaction, and determine the mass of copper(II) sulfate that would react with this quantity of zinc. ___ Zn(s) + ___CuSO4(aq) → ___ZnSO4(aq) + ___Cu(s)  (unbalanced)

A) 65.4 g

B) 0.641 g

C) 1.28 g

D) 2.56 g

E) 159 g

36) Small amounts of oxygen gas can be produced for laboratory use by heating potassium chlorate, which causes it to decompose by the following reaction: ___KClO3(s) → ____KCl(s) + ___O2(g) (unbalanced) Balance the equation, and determine the mass of oxygen that should be formed if 10.0 g of potassium chlorate decomposes.

A) 7.83 g

B) 115 g

C) 3.92 g

D) 38.3 g

E) 57.4 g

37) Small amounts of oxygen gas can be produced for laboratory use by heating potassium chlorate, which causes it to decompose by the following reaction: ___KClO3(s) → ____KCl(s) + ___O2(g) (unbalanced) Balance the equation, and determine the mass of oxygen that should be formed if 15.0 g of potassium chlorate decomposes.

A) 11.7 g

B) 57.5 g

C) 173 g

D) 5.88 g

E) 86.1 g

38) When mercury(II) oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: ___HgO(s) → ___Hg(l) + ___O2(g) (unbalanced) Balance the equation and determine the mass of mercury that should be formed when 12.3 g of HgO is heated.

A) 22.8 g

B) 11.4 g

C) 5.70 g

D) 13.3 g

E) 6.64 g

39) When mercury(II) oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: ___HgO(s) → ___Hg(l) + ___O2(g) (unbalanced) Balance the equation and determine the mass of mercury that should be formed when 15.6 g of HgO is heated.

A) 28.9 g

B) 7.22 g

C) 14.4 g

D) 16.9 g

E) 13.2 g

40) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of chlorine would be required to react with 10.6 g of phosphorus.

A) 6.07 g

B) 24.3 g

C) 36.4 g

D) 18.5 g

E) 74.1 g

41) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the following equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of chlorine would be required to react with 21.2 g of phosphorus.

A) 12.1 g

B) 48.6 g

C) 37.0 g

D) 148 g

E) 72.8 g

42) Nitrogen and hydrogen react together to form ammonia according to the equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen would be required to react with 25.2 g of nitrogen.

A) 1.82 g

B) 3.64 g

C) 5.45 g

D) 1.34 g

E) 0.891

43) Nitrogen and hydrogen react together to form ammonia according to the equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen would be required to react with 50.4 g of nitrogen.

A) 10.9 g

B) 3.64 g

C) 7.28 g

D) 2.68 g

E) 1.78 g

44) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of phosphorus reactant would be required to produce 25.0 g of phosphorus trichloride, assuming there is sufficient chlorine available.

A) 22.6 g

B) 45.1 g

C) 5.64 g

D) 111 g

E) 90.2 g

45) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the following equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of phosphorus reactant would be required to produce 75.0 g of phosphorus trichloride, assuming there is sufficient chlorine available.

A) 67.8 g

B) 135 g

C) 16.9 g

D) 271 g

E) 333 g

46) Nitrogen and hydrogen react together to form ammonia according to the following equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen reactant would be required to produce 50.0 g of ammonia, assuming there is sufficient nitrogen available.

A) 4.46 g

B) 5.94 g

C) 4.81 g

D) 8.91 g

E) not enough information

47) Nitrogen and hydrogen react together to form ammonia according to the equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen reactant would be required to produce 25.0 g of ammonia, assuming there is sufficient nitrogen available.

A) 2.23 g

B) 4.46 g

C) 2.97 g

D) 2.40 g

E) not enough information

48) When 3.0 mol CaCl2 dissolves in water, how many moles of ions are in solution?

A) 1.0 mole

B) 3.0 moles

C) 6.0 moles

D) 9.0 moles

E) 12 moles

49) When 5.0 g CaCl2 is dissolved in water, how many moles of ions are in solution?

A) 0.135 mole

B) 0.045 mole

C) 5.0 moles

D) 15.0 moles

E) 1660 moles

50) When 5.0 g CaCl2 is dissolved in enough water to make a 0.500 L solution, what is the molarity of ions in solution?

A) 0.135 M

B) 0.045 M

C) 0.270 M

D) 10.0 M

E) 2.50 M

51) If you have eight bicycle wheels and five frames, how many bikes could you build (assuming that each bike requires one frame and two wheels), and what would be left over?

A) Four bikes could be built, and nothing would be left over.

B) Four bikes could be built, and one frame would be left over.

C) Five bikes could be built, and three wheels would be left over.

D) Five bikes could be built, and nothing would be left over.

E) Three bikes could be built, and two frames would be left over.

52) If you wish to make sandwiches which consist of two slices of bread, one ham slice, and three pickle slices, how many sandwiches could you make if you have 12 slices of bread, five slices of ham, and 20 pickle slices, and what would be left over?

A) Six sandwiches could be made, and two pickle slices would be left over.

B) Four sandwiches could be made, and four slices of bread and eight pickle slices would be left over.

C) Five sandwiches could be made, and two slices of bread and five pickle slices would be left over.

D) Twelve sandwiches could be made, and there would be no leftovers.

E) Five sandwiches could be made, and two slices of bread and no pickle slices would be left over.

53) A pamphlet requires one cover, 14 pieces of white paper, and three sheets of colored paper. How many pamphlets could be made, and what would be left over, if there are 50 covers, 500 sheets of white paper, and 100 sheets of colored paper available?

A) 33 pamphlets could be made, and one sheet of colored paper, 38 sheets of white paper, and 17 covers would be left over.

B) 50 pamphlets could be made, and there would be no leftovers.

C) 650 pamphlets could be made, and there would be no leftovers.

D) 34 pamphlets could be made, and 24 sheets of white paper and 16 covers would be left over.

E) 35 pamphlets could be made, and 10 sheets of white paper and 15 covers would be left over.

54) Consider the following reaction: CrCl3(s) + KCl(s) + 2H2SO4(l) → KCr(SO4)2(s) + 4HCl(g) green white colorless purple colorless solid solid liquid solid gas When the green solid is mixed with the white solid and the colorless liquid is added, the mixture starts to bubble and fume. When all action has stopped, a wet purple solid containing solid white specks remains. Which substance is the limiting reactant?

A) CrCl3

B) KCl

C) H2SO4

D) KCr(SO4)2

E) HCl

55) Consider the following reaction: Cr2O3(s) + 3CCl4(l) → 2CrCl3(s) + 3COCl2(g) green colorless purple colorless solid liquid solid gas When the green solid is mixed with the colorless liquid, the mixture starts to bubble and fume. When all action has stopped, a dry purple solid containing solid green specks remains. Which substance is the limiting reactant?

A) Cr2O3

B) CCl4

C) CrCl3

D) COCl2

E) there is no limiting reactant

56) Consider the following reaction: Cr2O3(s) + 3CCl4(l) → 2CrCl3(s) + 3COCl2(g) green colorless purple colorless solid liquid solid gas When the green solid is mixed with the colorless liquid, the mixture starts to bubble and fume. When all action has stopped, a wet purple solid remains. Which substance is the limiting reactant?

A) Cr2O3

B) CCl3

C) CrCl3

D) COCl2

E) there is no limiting reactant

57) Phosphorus trichloride can be made by the following reaction: P4(s) + 6Cl2(g) → 4PCl3(l) What is the maximum amount of phosphorus trichloride that can be formed if 10 molecules of P4 are mixed with 36 molecules of chlorine?

A) 4 molecules

B) 6 molecules

C) 12 molecules

D) 24 molecules

E) 46 molecules

58) Phosphorus trichloride can be made by the following reaction: P4(s) + 6Cl2(g) → 4PCl3(l) What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P4 are mixed with 42 molecules of chlorine?

A) 4 molecules

B) 12 molecules

C) 24 molecules

D) 28 molecules

E) 57 molecules

59) Ammonia is usually made by the following reaction: N2(g) + 3H2(g) → 2NH3(g) What is the maximum amount of ammonia that can be formed if 25 molecules of nitrogen are mixed with 60 molecules of hydrogen?

A) 20 molecules

B) 25 molecules

C) 30 molecules

D) 40 molecules

E) 85 molecules

60) Ammonia is usually made by the following reaction: N2(g) + 3H2(g) → 2NH3(g) What is the maximum amount of ammonia that can be formed if 30 molecules of nitrogen are mixed with 100 molecules of hydrogen?

A) 20 molecules

B) 30 molecules

C) 40 molecules

D) 60 molecules

E) 70 molecules

61) The figure shows a molecular-level diagram of reactant molecules for the reaction   2H2(g) + O2(g) → 2H2O(l)

List the number and formulas of the molecules that should be present after the reaction takes place.

A) 2H2O + 6H2 + 2O2

B) 3H2O + 5H2 + O2

C) 4H2O + 4H2 + O2

D) 6H2O + 2H2 + O2

E) 6H2O + 2H2

62) The figure shows a molecular-level diagram of reactant molecules for the reaction:  2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)

 List the number and formulas of the molecules that should be present after the reaction takes place.

A) 4CO2 + 2H2O

B) 4CO2 + 2H2O + 2C2H2

C) 4CO2 + 2H2O + 2C2H2 + 5O2

D) 6CO2 + 3H2O + 3O2

E) 8CO2 + 4H2O + 2C2H2

63) Consider the reaction N2(g) + O2(g) → 2NO(g). The molecular image represents a mixture of N2(g) and O2(g) just before reaction occurs. What is the limiting reactant, and how much of the excess reactant remains after the reaction is complete? The image contains 2 N2 molecules and 4 O2 molecules.

A) N2(g), 1 O2(g)

B) N2(g), 2 O2(g)

C) N2(g), 3 O2(g)

D) O2(g), 1 N2(g)

E) N2(g), 0 O2(g)

64) Consider the reaction N2(g) + 2O2(g) → 2NO2(g). The molecular image represents a mixture of N2(g) and O2(g) just before reaction occurs. What is the limiting reactant, and how much of the excess reactant remains after the reaction is complete? The image contains 3 N2 molecules and 9 O2 molecules.

A) N2(g), 6 O2(g)

B) O2(g), 1 N2(g)

C) N2(g), 3 O2(g)

D) O2(g), 2 N2(g)

E) N2(g), 7 O2(g)

65) Nitrogen monoxide reacts with oxygen according to the following reaction:  2NO(g) + O2(g) → 2NO2(g) If 12 moles of nitrogen monoxide are combined with 10 moles of oxygen, how many moles of NO2 should form?

A) 2 moles

B) 5 moles

C) 6 moles

D) 10 moles

E) 12 moles

66) Nitrogen monoxide reacts with oxygen according to the following reaction:  2NO(g) + O2(g) → 2NO2(g) If 10 moles of nitrogen monoxide are combined with 4 moles of oxygen, how many moles of NO2 should form?

A) 4 moles

B) 8 moles

C) 10 moles

D) 12 moles

E) 14 moles

67) Aluminum reacts with oxygen according to the following reaction:  4Al(s) + 3O2(g) → 2Al2O3(s) If 24 moles of aluminum are combined with 12 moles of oxygen, how many moles of Al2O3 should form?

A) 4.0 moles

B) 8.0 moles

C) 6.0 moles

D) 5.0 moles

E) 26 moles

68) Aluminum reacts with oxygen according to the following reaction:  4Al(s) + 3O2(g) → 2Al2O3(s) If 12 moles of aluminum are combined with 6 moles of oxygen, how many moles of Al2O3 should form?

A) 4 moles

B) 8 moles

C) 6 moles

D) 12 moles

E) 20 moles

69) Consider the following reaction: 3NO2(g) + H2O(l) → 2HNO3(l) + NO(g) How many moles of NO2 are required to react with 1.50 moles of H2O to form 3.00 moles of HNO3?

A) 1.50 mol

B) 3.00 mol

C) 4.00 mol

D) 4.50 mol

E) 9.00 mol

70) Consider the following reaction: 3NO2(g) + H2O(l) → 2HNO3(l) + NO(g) How many moles of the excess reactant remain if 4.00 moles of H2O and 10.00 moles of NO2 are mixed?

A) 0.67 mol H2O

B) 2.00 mol NO2

C) 3.33 mol H2O

D) 6.00 mol NO2

E) 8.00 mol NO2

71) Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl2(g) → 2FeCl3(s) If 35.0 g each of iron and chlorine are combined, how much FeCl3 should form?

A) 102 g

B) 155 g

C) 53.4 g

D) 80.0 g

E) 68.0 g

72) Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl2(g) → 2FeCl3(s) If 25.6 g each of iron and chlorine are combined, how much FeCl3 should form?

A) 74.3 g

B) 113 g

C) 39.0 g

D) 49.5 g

E) 26.0 g

73) In the process of obtaining lead from PbS, or galena, the galena is "roasted" (heated in the presence of oxygen), so that the following reaction occurs: 2PbS(s) + 3O2(g) → 2PbO(s) + 2SO2(g) If 50.0 g of PbS are mixed with 25.0 g of oxygen, how many grams of PbO should form?

A) 116 g

B) 46.6 g

C) 163 g

D) 69.9 g

E) 93.2 g

74) In the process of obtaining lead from PbS, or galena, the galena is "roasted" (heated in the presence of oxygen), so that the following reaction occurs:  2PbS(s) + 3O2(g) → 2PbO(s) + 2SO2(g) If 35.2 g of PbS is mixed with 15.5 g of oxygen, how many grams of PbO should form?

A) 32.8 g

B) 72.1 g

C) 105 g

D) 65.7 g

E) 49.2 g

75) What mass (in grams) of SF6 should be produced by the following reaction if 7.00 g of sulfur is mixed with 9.00 g of fluorine? S + 3F2 → SF6

A) 24.0

B) 6.40

C) 11.1

D) 32.0

E) 16.0

76) If the theoretical yield for a reaction is 54.9 g, and 51.3 g of product are actually obtained, the percent yield is

A) 0.934%.

B) 93.4%.

C) 107%.

D) 3.60%.

E) not enough information given.

77) If the theoretical yield for a reaction is 29.4 g, and 28.7 g of product are actually obtained, what is the percent yield?

A) 0.976%

B) 102%

C) 97.6%

D) 0.700%

E) not enough information given

78) If the theoretical yield for a reaction is 72.3 g, and 65.2 g of product are actually obtained, what is the percent yield?

A) 90.2%

B) 0.902%

C) 7.10%

D) 111%

E) not enough information given

79) Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H2SO4(aq) → Al2(SO4)3(s) + 3H2(g) If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

A) 63.4%

B) 85.5%

C) 117%

D) 47.1%

E) not enough information given

80) Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H2SO4(aq) → Al2(SO4)3(s) + 3H2(g) If 12.9 g of aluminum reacts with excess sulfuric acid, and 62.4 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

A) 81.8%

B) 49.5%

C) 76.3%

D) 131%

E) not enough information given

81) Iron metal reacts with hydrochloric acid as follows: 2Fe(s) + 6HCl(aq) → 2FeCl3(aq) + 3H2(g) If 22.4 g of iron react with excess HCl, and 59.4 g of FeCl3 are collected, what is the percent yield of Al2(SO4)3?

A) 65.0%

B) 109%

C) 91.4%

D) 73.0%

E) not enough information given

82) Iron metal reacts with hydrochloric acid as follows: 2Fe(s) + 6HCl(aq) → 2FeCl3(aq) + 3H2(g) If 35.6 g of iron react with excess HCl, and 98.6 g of FeCl3 are collected, what is the percent yield of FeCl3?

A) 103%

B) 104%

C) 95.7%

D) 63.0%

E) not enough information given

83) Which of the following best describes an exothermic reaction?

A) Heat must be added to get the reaction to go

B) The temperature of the surroundings decreases

C) The potential energy of the reactants is greater than that of the surroundings

D) Matter is converted into energy

E) Heat is absorbed by the reaction from the surroundings

84) Which of the following processes is exothermic?

A) ice melting in a beverage

B) dry ice (solid CO2) converting to a gas at room temperature

C) evaporation of water from a mud puddle

D) burning propane in a barbeque grill

E) wax melting on the top of a burning candle

85) Which of the following is an exothermic process?

A) ice melting

B) water evaporating

C) boiling soup

D) condensation of water vapor

E) Ammonium thiocyanate and barium hydroxide are mixed, resulting in a decrease in temperature of the surroundings

86) Which of the following processes is endothermic?

A) burning gasoline in an internal combustion engine

B) evaporation of perspiration on your skin

C) burning wood in a fireplace

D) condensing steam on a mirror

E) hot coffee cooling down as it sits on the table

87) Which of the following is an exothermic process?

A) ice melting

B) water evaporating

C) boiling soup

D) condensation of water vapor

E) Ammonium thiocyanate and barium hydroxide are mixed, resulting in a decrease in temperature

88) Which of the following processes is exothermic?

A) boiling water to make tea

B) cooking an egg

C) heating food in a microwave oven

D) an acid and base reacting together, and causing the solution to become warm

E) water in a swimming pool getting warmer in the sun

89) The following reaction absorbs 393 kJ of heat for each mole of CO2 that reacts. CO2(g) → C(s) + O2(g) This reaction

A) is endothermic and has a positive value of q.

B) is exothermic and has a positive value of q.

C) is endothermic and has a negative value of q.

D) is exothermic and has a negative value of q.

90) The following reaction releases 2800 kJ of heat for each mole of C6H12O6 that reacts. C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l) This reaction is

A) endothermic and has a positive value of q.

B) exothermic and has a positive value of q.

C) endothermic and has a negative value of q.

D) exothermic and has a negative value of q.

91) Consider the following specific heats of metals.

If the same amount of heat is added to 25.0 g of each of these metals, all at the same initial temperature, which metal will have the highest final temperature?

A) copper

B) calcium

C) aluminum

D) iron

E) lead

92) Consider the following specific heats of metals.  

If the same amount of heat is added to 50.0 g of each of these metals, all at the same initial temperature, which metal will have the lowest final temperature?

A) copper

B) calcium

C) aluminum

D) iron

E) lead

93) If 75.0 J of heat energy is added to 25.0 g samples of different metals. Given their specific heat values, rank the metals in order from least to greatest final temperature.  

A) Au < Ag < Cu < Cr < Al

B) Al < Cr < Cu < Ag < Au

C) Au < Ag < Al < Cr < Cu

D) Cr < Cu < Al < Ag < Au

E) none of these—all final temperatures would be equal

94) An equal quantity of heat is transferred to 10.0 g samples of different substances. Given their specific heat values, rank the substances in order from least to greatest final temperature.

A) iron < glass < concrete < asphalt < water

B) water < asphalt < concrete < glass < iron

C) asphalt < concrete < glass < iron < water

D) iron < concrete < glass < asphalt < water

E) water < concrete < asphalt < glass < iron

95) A carton of low-fat yogurt says it has 1.70 x 102 Calories. What is the equivalent amount of energy in units of joules?

A) 711 J

B) 7.11 x 105 J

C) 4.06 x 104 J

D) 406 J

E) 40.6 J

96) A can of soda has 1.50 x 102 Calories. Convert this energy to units of joules.

A) 628 J

B) 6280 J

C) 35.9 J

D) 3.59 x 104 J

E) 6.28 x 105 J

97) A 43 g serving of a chocolate candy has 2.10 x 102 Calories. Convert this energy to units of joules.

A) 879 J

B) 8.79 x 105 J

C) 50.2 J

D) 5.02 x 104 J

E) 8.79 x 103 J

98) When carbon dioxide is formed from its elements, 393.5 kJ of energy is released. Convert this energy to units of calories.

A) 9.405 x 104 cal

B) 94.05 cal

C) 0.3935 cal

D) 1.646 x 103 cal

E) 1.646 x 106 cal

99) When sulfur dioxide is formed from its elements, 296.8 kJ of energy is released. Convert this energy to units of calories.

A) 70.94 cal

B) 7.094 x 104 cal

C) 0.2968 cal

D) 1.242 x 103 cal

E) 1.242 x 106 cal

100) An energy input of 227 kJ is required to form acetylene from its elements. Convert this energy to units of calories.

A) 9.50 x 102 cal

B) 9.50 x 105 cal

C) 0.227 cal

D) 54.3 cal

E) 5.43 x 104 cal

101) Equal masses of ice at 0°C and water at 100°C are mixed in an insulated container. Estimate the final temperature of the mixture.

A) between 51 and 99°C

B) between 1 and 49ºC

C) 50°C

D) 0°C

E) 100°C

102) How much heat energy would be needed to raise the temperature of a 15.0 g sample of iron [C = 0.448 J/(g°C)] from 22.0°C to 100.0°C?

A) 34.9 J

B) 672 J

C) 524 J

D) 1.17 x 103 J

E) not enough information given

103) How much heat energy would be needed to raise the temperature of a 22.3 g sample of aluminum [(C = 0.895 (J/g°C)] from 22.5°C to 55.0°C?

A) 20.0 J

B) 649 J

C) 725 J

D) 8.10 x 102 J

E) not enough information given

104) How much heat energy would be needed to raise the temperature of a 32.0 g sample of gold [C = 0.129 (J/g°C)] from 21.8°C to 75.0°C?

A) 3.10 x 102 J

B) 1.32 x 104 J

C) 2.20 x 102 J

D) 90.0 J

E) not enough information given

105) What is the heat change when a 53.5 g sample of water [Cwater = 4.184 J/(g°C)] is cooled from 98.0°C to 23.2°C?

A) 1.67 x 104 J

B) −1.67 x 104 J

C) 2.19 x 104 J

D) −956 J

E) not enough information given

106) What is the heat change when a 26.8 g sample of water [Cwater = 4.184 J/(g°C)] is cooled from 75.6°C to 22.1°C?

A) 6.00 x 103 J

B) −6.00 x 103 J

C) 1.43 x 103 J

D) −1.43 x 103 J

E) not enough information given

107) What is the heat change when a 225 g sample of olive oil [Cwater = 1.79 J/(g°C)] is cooled from 95.8°C to 52.1°C?

A) 9.83 x 103 J

B) −9.83 x 103 J

C) −1.76 x 104 J

D) 1.76 x 104 J

E) not enough information given

108) A 5.00 g sample of a brownie was burned in a bomb calorimeter containing 2025 g of water. The temperature of the water increased from 23.50°C to 33.47°C. How much heat, in joules, did the brownie release when it burned? [Cwater = 4.184 J/(g°C)]

A) 1.99 x 105 J

B) 2.80 x 105 J

C) 4.92 x 102 J

D) 8.45 x 104 J

E) 7.00 x 102 J

109) A 2.50 g sample of pitted prunes was burned in a bomb calorimeter containing 2110 g of water. The temperature of the water increased from 22.50°C to 25.76°C. How much heat, in joules, did the prune sample release when it burned? [Cwater = 4.184 J/(g°C)]

A) 1.99 x 105 J

B) 2.27 x 105 J

C) 2.88 x 104 J

D) 2.35 x 102 J

E) 2.69 x 102 J

110) A 3.50 g sample of rice was burned in a bomb calorimeter containing 1980 g of water. The temperature of the water increased from 22.75°C to 28.88°C. How much heat, in joules, did the rice sample release when it burned? [Cwater = 4.184 J/(g°C)]

A) 1.88 x 105 J

B) 2.39 x 105 J

C) 5.08 x 104 J

D) 3.33 x 102 J

E) 4.22 x 102 J

111) The q value for the following reaction is 178.0 kJ for every mole of CaCO3 that reacts: CaCO3(s) → CaO(s) + CO2(g) How much heat would be required to decompose 4.00 mol CaCO3(s), and is the reaction endothermic or exothermic?

A) 712 kJ; exothermic

B) 712 kJ; endothermic

C) 178 kJ; exothermic

D) 44.5 kJ; endothermic

E) 44.5 kJ; exothermic

112) The coefficients of a balanced equation can be understood to represent either relative numbers of molecules or moles.

113) The coefficients of a balanced equation can be understood to represent either relative numbers of moles or relative mass.

114) The number of moles of reactant molecules must always equal the number of moles of product molecules in a balanced equation.

115) The limiting reactant in a chemical reaction is always the reactant which is present in the least amount in terms of mass.

116) When calculating the percent yield for a reaction, the only information necessary is the mass of each reactant.

117) A calorie used by nutritionists, 1 Calorie, is equal to 1000 cal or 1 kcal used by chemists.

118) One calorie is the amount of heat energy required to raise the temperature of 10.0 g of water by 1°C.

119) When a substance cools from a high temperature to a low temperature, its heat change value will have a negative sign.

120) The specific heat of a substance is the amount of heat energy that is needed to cause the substance to melt.

121) In a bomb calorimeter, the bomb itself, the water surrounding it, and the thermometer would be considered part of the "system."

122) When fats or other foods are burned in a bomb calorimeter, the calorimeter absorbs heat, so the reaction is endothermic.

123) When blue copper(II) sulfate pentahydrate is heated, it decomposes according to the equation given below, forming light blue copper(II) sulfate and water vapor. CuSO4·5H2O(s) → CuSO4(s) + 5H2O(g) If a 5.00 g sample of CuSO4·5H2O is heated, what mass of CuSO4 will be formed when the reaction is complete? Report your answer with the correct number of significant figures and correct units.

124) When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the following equation: 4K(s) + O2(g) → 2K2O(s) If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of oxygen reacted with the potassium? Report your answer with the correct number of significant figures and correct units.

125) When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the following equation: 4K(s) + O2(g) → 2K2O(s) If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of potassium reacted? Report your answer with the correct number of significant figures and correct units.

126) When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the following equation: 4K(s) + O2(g) → 2K2O(s) If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of K2O formed? Report your answer with the correct number of significant figures and correct units.

127) The combustion of octane is described by the following balanced equation: 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(g) If 50.0 g of each reactant are available to react, how much CO2 should form? Report your answer with the correct number of significant figures and correct units.

128) An aqueous solution containing 15.0 g of NaOH is mixed with an aqueous solution containing 15.0 g of H2SO4. Is sodium hydroxide or sulfuric acid the limiting reactant?

129) An aqueous solution containing 15.0 g of NaOH is mixed with an aqueous solution containing 15.0 g of H2SO4. Will the solution be acidic or basic when the reaction is complete?

130) In photosynthesis, plants convert carbon dioxide and water into glucose, C6H12O6, according to the reaction: 6CO2(g) + 6H2O(l) → 6O2(g) + C6H12O6(g) How many grams of glucose can be synthesized from 117 g of CO2, assuming there is sufficient water to react with all of the CO2? Report your answer with the correct number of significant figures and correct units.

131) How much heat must be added to 125 g of copper [C = 0.377 J/(g°C)] at 25.0°C to raise its temperature to 78.4°C? Report your answer with the correct number of significant figures and correct units.

132) The burning of a 2.50 g sample of pizza in a bomb calorimeter gives off 2.53 x 104 J of energy. If the calorimeter contains 2440 g of water, what was the temperature change of the water? [Cwater = 4.184 J/(g°C)] Report your answer with the correct number of significant figures.

133) In photosynthesis, plants convert carbon dioxide and water into glucose, C6H12O6, according to the reaction: 6CO2(g) + 6H2O(l) → 6O2(g) + C6H12O6(g) If 75.2 g of glucose are obtained when 131 g of CO2 react in the presence of excess H2O, what is the percent yield of the reaction? Report your answer with the correct number of significant figures.