1.
Hydrogen and nitrogen react to form ammonia according to the reaction, 3 H2 + N2 à 2 NH3. If 4.0 moles of H2 with 2.0 mol of N2 react, how many moles of NH3 would be produced?
A) 0.38 mol
B) 2.0 mol
C) 2.7 mol
D) 4.0 mol
2.
Hydrogen and nitrogen react to form ammonia according to the reaction, 3 H2 + N2 à 2 NH3. If 4.0 moles of H2 with 2.0 mol of N2 react, how many moles of what reactant is left over?
A) 0.7 mol of N2
B) 1.3 mol of N2
C) 2 mol H2
D) 6 mol H2
3.
In the reaction Zn + 2 HCl à ZnCl2 + H2, 25.0 grams (g) of Zn react with 17.5 g of HCl. How many grams of H2 are produced?
A) 0.382 g of H2
B) 0.479 g H2
C) 0.765 g H2
D) 25.0 g H2
5.
Consider the equation A + 3B à 4C. If 3.0 moles of A react with 6.0 moles of B, which is true after the reaction is complete?
A) A is the leftover reactant because only 2 moles of A are needed, but 3 moles are present.
B) A is the leftover reactant because, for every 1 mole of A, 4 moles of C are produced.
C) B is the leftover reactant because there are more moles of B than A.
D) D is the leftover reactant because there are more moles of B than A.
6.
Metallic copper is formed when aluminum reacts with copper (II) sulfate. How many grams of metallic copper can be obtained when 54.0 g of Al react with 319 g of CuSO4? Al + 3CuSO4 à Al2 (SO4) 3 + 3Cu
A) 21.2 g
B) 127 g
C) 162 g
D) 381 g
7.
How could you determine the excess amount of reactant left over in a chemical reaction?
A) This cannot be determined.
B) Subtract the number of moles of product actually recovered from what was calculated.
C) Subtract the number of moles of excess reactant used from what was present.
D) Subtract the number of moles of excess reactant used from the limiting reactant.
9.
For the reaction 2Na + Cl2 à 2NaCl, calculate the percentage yield if 200. g of chlorine react with excess sodium to produce 240. g of sodium chloride.
A) 61.2%
B) 72.8%
C) 83.4%
D) 88.4%
10.
For the reaction CH4(g) + 2O2(g) à CO2(g) + 2H2O(g), calculate the percentage yield of carbon dioxide if 1000. g of methane react with excess oxygen to produce 2300. g of carbon dioxide.
A) 83.88%
B) 89.14%
C) 92.76%
D) 96.78%
12.
Lead nitrate may be decomposed by heating. What is the percent yield of the decomposition reaction if 9.9 g Pb(NO3) 2 are heated to give 5.5 g of PbO? 2Pb(NO3)2 (s) à 2PbO(s) + 4NO2 (g) + O2 (g)
A) 44%
B) 56%
C) 67%
D) 82%
13.
27.0 g of silver reacts with excess sulfur according to the following equation: 2 Ag + S à Ag2S. 25.0 grams of silver sulfide was collected in a lab. What is the theoretical yield?
A) 25.0 g
B) 27.0 g
C) 31.0 g
D) 13.5 g
14.
27.0 g of silver reacts with excess sulfur according to the following equation: 2 Ag + S à Ag2S. 25.0 grams of silver sulfide was collected in a lab. What is the actual yield?
A) 25.0 g
B) 27.0 g
C) 31.0 g
D) 54.0 g
Hydrogen and nitrogen react to form ammonia according to the reaction, 3 H2 + N2 à 2 NH3. If 4.0 moles of H2 with 2.0 mol of N2 react, how many moles of NH3 would be produced?
A) 0.38 mol
B) 2.0 mol
C) 2.7 mol
D) 4.0 mol
2.
Hydrogen and nitrogen react to form ammonia according to the reaction, 3 H2 + N2 à 2 NH3. If 4.0 moles of H2 with 2.0 mol of N2 react, how many moles of what reactant is left over?
A) 0.7 mol of N2
B) 1.3 mol of N2
C) 2 mol H2
D) 6 mol H2
3.
In the reaction Zn + 2 HCl à ZnCl2 + H2, 25.0 grams (g) of Zn react with 17.5 g of HCl. How many grams of H2 are produced?
A) 0.382 g of H2
B) 0.479 g H2
C) 0.765 g H2
D) 25.0 g H2
5.
Consider the equation A + 3B à 4C. If 3.0 moles of A react with 6.0 moles of B, which is true after the reaction is complete?
A) A is the leftover reactant because only 2 moles of A are needed, but 3 moles are present.
B) A is the leftover reactant because, for every 1 mole of A, 4 moles of C are produced.
C) B is the leftover reactant because there are more moles of B than A.
D) D is the leftover reactant because there are more moles of B than A.
6.
Metallic copper is formed when aluminum reacts with copper (II) sulfate. How many grams of metallic copper can be obtained when 54.0 g of Al react with 319 g of CuSO4? Al + 3CuSO4 à Al2 (SO4) 3 + 3Cu
A) 21.2 g
B) 127 g
C) 162 g
D) 381 g
7.
How could you determine the excess amount of reactant left over in a chemical reaction?
A) This cannot be determined.
B) Subtract the number of moles of product actually recovered from what was calculated.
C) Subtract the number of moles of excess reactant used from what was present.
D) Subtract the number of moles of excess reactant used from the limiting reactant.
9.
For the reaction 2Na + Cl2 à 2NaCl, calculate the percentage yield if 200. g of chlorine react with excess sodium to produce 240. g of sodium chloride.
A) 61.2%
B) 72.8%
C) 83.4%
D) 88.4%
10.
For the reaction CH4(g) + 2O2(g) à CO2(g) + 2H2O(g), calculate the percentage yield of carbon dioxide if 1000. g of methane react with excess oxygen to produce 2300. g of carbon dioxide.
A) 83.88%
B) 89.14%
C) 92.76%
D) 96.78%
12.
Lead nitrate may be decomposed by heating. What is the percent yield of the decomposition reaction if 9.9 g Pb(NO3) 2 are heated to give 5.5 g of PbO? 2Pb(NO3)2 (s) à 2PbO(s) + 4NO2 (g) + O2 (g)
A) 44%
B) 56%
C) 67%
D) 82%
13.
27.0 g of silver reacts with excess sulfur according to the following equation: 2 Ag + S à Ag2S. 25.0 grams of silver sulfide was collected in a lab. What is the theoretical yield?
A) 25.0 g
B) 27.0 g
C) 31.0 g
D) 13.5 g
14.
27.0 g of silver reacts with excess sulfur according to the following equation: 2 Ag + S à Ag2S. 25.0 grams of silver sulfide was collected in a lab. What is the actual yield?
A) 25.0 g
B) 27.0 g
C) 31.0 g
D) 54.0 g