AP Chemistry Review Questions - Reaction Stoichiometry
Butane, CH3-CH2-CH2-CH3, is a hydrocarbon fuel used in lighters. How many moles of molecules are there in a 350. gram sample of butane?
6 mol
6.02 mol
0.170 mol
20349 mol
20300 mol
For which of the following compounds does 0.400 mol have a mass of 12.8 grams?
CH4
CCl4
CO2
C4H10
CH3OH
What is the molar mass of glucose, C6H12O6?
160.00 g
180.18 g
18 g
12.01 g
220.17 g
Methane, CH4, and ethane, C2H6 are both hydrocarbons that exist as gases at room conditions. How many grams of ethane contain the same number of molecules as 6.00 g of methane?
11.2 grams
.374 grams
80.5 grams
0.09 grams
2896 grams
A substance with the formula AB has the composition by mass of 30% A and 70% B. What is the composition by mass of the compound A2B?
65% A, 35% B
70% A, 30% B
46% A, 54% B
60% A, 40% B
50% A, 50% B
How grams of oxygen are present in a 30.0 gram sample of potassium chlorate?
36.8 grams
7.83 grams
3.83 grams
150.45 grams
11.8 grams
18.0 grams of carbon is burned in 55.0 grams of oxygen. How many grams of carbon dioxide are formed?
151 grams CO2
75.6 grams CO2
66.0 grams CO2
44.01 grams CO2
12.01 grams CO2
When the equation for the combustion of ethane, C2H6, is correctly balanced, the coefficient on oxygen is:
1
3
5
7
9
Given the equation 3A + 4B → 2C + 3D, you react 5 moles of A with 7 moles of B. Which of the following statements is true?
A is the limiting reactant
B is the limiting reactant
A and B are in ideal stoichiometric proportions
A has a greater molar mass than B
B has a greater molar mass than A
A chemistry student decomposes a 78.0 gram sample of potassium chlorate, using manganese dioxide as a catalyst. Her effort yields 24.247 grams of oxygen. What is her percent yield?
30.1%
79.2%
20.8%
59.9%
The answer cannot be calculated from the information provided.
When 13.5 grams of methane (CH4) burns in 40.0 grams of oxygen, how many grams of water are formed?
30.3 grams H2O
24.0 grams H2O
18.0 grams H2O
112 grams H2O
22.5 grams H2O
A mass of 21.5 grams of calcium hydroxide reacts with an excess of phosphoric acid. What mass of calcium phosphate could be recovered from solution?
326 grams
31.6 grams
94.7 grams
284 grams
186 grams
A mass of 21.5 grams of calcium hydroxide reacts with an excess of phosphoric acid. How many atoms of oxygen are found in the water produced in the reaction?
1.75 x 1023 atoms
3.49 x 1023 atoms
8.75 x 1022 atoms
7.0 x 1023 atoms
1.05 x 1024 atoms
A 5.15 gram sample of a hydrocarbon is burned in oxygen, producing 15.6 grams of carbon dioxide and 8.45 grams of water. Assuming an excess of oxygen, what is the empirical formula of the hydrocarbon?
CH4
C3H8
C5H12
C7H16
C9H20
A sample of an alcohol is tested and found to contain 52% carbon, 35% oxygen, and 13% hydrogen by mass. Tests indicate that the molecular weight of the molecule is between 30 and 80. What is the molecular formula of the alcohol?