1)For the reaction of C2H4(g) with O2(g) to form CO2(g) and H2O(g), what number of grams of CO2 could be produced from 2.0 g of C2H4 and 3.8 g of O2?
2)A gaseous compound containing carbon and hydrogen was analyzed and found to consist of 83.65% carbon by mass. What is the empirical formula of the compound?
A) CH2
B) CH3
C) C7H16
D) CH
E) C3H7
3)Consider a reaction in which two reactants make one product (for example, consider the unbalanced reaction A + B ? C). You know the following:
2.0 mol A (with an excess of B) can produce a maximum of 2.0 mol C
3.0 mol B (with an excess of A) can produce a maximum of 4.0 mol C
If you react 2.0 mol A with 3.0 mol B, what is the maximum amount of C that can be produced?
A) 2.0 mol
B) 4.0 mol
C) 5.0 mol
D) 6.0 mol
E) More information is needed to answer this question
4)An aqueous solution of ammonium sulfate is allowed to react with an aqueous solution of lead(II) nitrate.
The net ionic equation contains which of the following species (when balanced in standard form)?
A) 2NH4+(aq)
B) 2SO42-(aq)
C) 2NO3-(aq)
D) Pb3+(aq)
E) NO3-(aq)
5)Consider that calcium metal reacts with oxygen gas in the air to form calcium oxide. Suppose we react 6.95 mol calcium with 4.00 mol oxygen gas. Determine the number of moles of oxygen left over after the reaction is complete.
A) 3.47 mol O2
B) 2.95 mol O2
C) 0.52 mol O2
D) 4.00 mol O2
E) none of these
6)Consider the following reaction, where X represents an unknown element:
6X(s) + 2B2O3(s) ? B4X3(s) + 3XO2(g)
If 175 g of X reacts completely with diboron trioxide to produce 2.43 mol of B4X3, what is the identity of X?
A) Ge
B) Mg
C) Si
D) N
E) C
7) For the reaction of C2H4(g) with O2(g) to form CO2(g) and H2O(g), what number of moles of CO2 can be produced by the reaction of 5.00 mol C2H4 and 13.4 mol O2?
A) 20.1 mol
B) 13.4 mol
C) 8.93 mol
D) 10.0 mol
E) none of these
8. A gas is 92.3% carbon and 7.7% hydrogen (by mass), and its molar mass is 26 g/mol. What is its molecular formula?
A) CH
B) C2H2
C) CH4
D) C4H4
E) none of these
9. The equation 2C2H6 + 7O2 ? 4CO2 + 6H2O is an oxidation-reduction reaction. True or false, and why?
A) True; the carbon is oxidized, and the oxygen is reduced.
B) True; the carbon is reduced, and the oxygen is oxidized.
C) True; the carbon is oxidized, and the hydrogen is reduced.
D) True; the oxygen is reduced, and the hydrogen is oxidized.
E) False
10. Consider the equation: A + 3B ? 2C. The molar mass of B is 50.0 g/mol. Which of the following statements is true when equal masses of A and B are reacted?
A) If the molar mass of A is greater than the molar mass of B, then A must determine how much C is produced.
B) If the molar mass of A is less than the molar mass of B, then A must determine how much C is produced.
C) If the molar mass of A is the same as the molar mass of B, then A and B react in a perfect stoichiometric ratio and both determine how much C is produced.
D) If the molar mass of A is greater than the molar mass of B, then B must determine how much C is produced.
E) If the molar mass of A is less than the molar mass of B, then B must determine how much C is produced.
11. Use the following choices to classify the reaction given below (more than one choice may apply).
P4(s) + 5O2(g) ? P4O10(s)
A) oxidation-reduction
B) combustion
C) synthesis
D) decomposition
12. A compound is composed of element X and hydrogen. Analysis shows the compound to be 80% X by mass, with three times as many hydrogen atoms as X atoms per molecule. Which element is element X?
A) C
B) He
C) F
D) S
E) none of these
13. How many grams of fluorine are contained in 6 molecules of boron trifluoride?
A) 1.893 x 10-22 g
B) 6.310 x 10-23 g
C) 5.679 x 10-22 g
D) 2.060 x 1026 g
E) 6.022 x 1023 g
14. Refer to the following equation: 4NH3(g) + 7O2((g) ? 4NO2((g) + 6H2(O(g)
How many molecules of water are produced if 5.95 mol of NO2 is given off?
A) 7.17 × 1024
B) 3.58 × 1024
C) 107.1
D) 5.37 × 1024
E) none of these
15. How many electrons are transferred in the following oxidation-reduction reaction?
Zn(s) + 2AgNO3(aq) ? Zn(NO3)2(aq) + 2Ag(s)
A) 1
B) 2
C) 3
D) 4
E) 5
16. The rusting of iron is represented by the equation 4Fe + 3O2 ? 2Fe2O3. If you have a 1.30-mol sample of iron, how many moles of Fe2O3 will there be after the iron has rusted completely?
A) 0.433 mol
B) 0.650 mol
C) 0.87 mol
D) 1.30 mol
E) 1.95 mol
17. How many of the following are oxidation-reduction reactions?
I. reaction of a metal with a nonmetal
II. synthesis
III. combustion
IV. precipitation
V. decomposition
A) 1
B) 2
C) 3
D) 4
E) 5
18. Consider the following reaction:
2A + B ? 3C + D
3.19 mol A and 2.00 mol B react to form 4.00 mol C. What is the percent yield of this reaction?
A) 16.4%
B) 55.7%
C) 41.8%
D) 83.6%
E) 100.%
19. A 37.8-mL sample of Hg (density = 13.6 g/mL) contains how many atoms of Hg?
A) 3.10 × 1026 atoms
B) 1.03 × 105 atoms
C) 6.21 × 1028 atoms
D) 1.54 × 1024 atoms
E) none of these
20. Consider the reaction of magnesium metal with hydrochloric acid to produce magnesium chloride and hydrogen gas. If 3.13 mol of magnesium and 3.13 mol of hydrochloric acid are reacted, how many moles of excess reactant are left over?
A) 6.26 mol
B) 3.13 mol
C) 2.35 mol
D) 38.0 mol
E) 1.57 mol