Chemistry Multiple Choice Quiz

Name: __________________________ Date: _____________

1.
Suppose the reaction Ca3(PO4)2 + 3H2SO4 3CaSO4 + 2H3PO4 is carried out starting with 103 g of Ca3(PO4)2 and 48.8 g of H2SO4. How much phosphoric acid will be produced?
A)
48.8 g
B)
32.5 g
C)
131.2 g
D)
73.2 g
E)
65.1 g

2.
Naturally occurring element X exists in three isotopic forms: X-28 (27.979 amu, 92.21% abundance), X-29 (28.976 amu, 4.70% abundance), and X-30 (29.974 amu, 3.09% abundance). Calculate the atomic weight of X.
A)
28.09 amu
B)
35.29 amu
C)
28 amu
D)
86.93 amu
E)
25.80 amu

3.
The Claus reactions, shown below, are used to generate elemental sulfur from hydrogen sulfide.

2H2S + 3O2 2SO2 + 2H2O

SO2 + 2H2S 3S + 2H2O

How much sulfur (in grams) is produced from 31.2 grams of O2?
A)
140.7 g
B)
20.8 g
C)
31.3 g
D)
62.5 g
E)
none of these

4.
How many moles of hydrogen sulfide are contained in a 69.5-g sample of this gas?
A)
0.49 mol
B)
2.04 mol
C)
103.6 mol
D)
34.5 mol
E)
4.08 mol

5.
How many atoms of hydrogen are present in 5.9 g of water?
A)
2.0e23
B)
1.8e24
C)
7.1e24
D)
3.9e23
E)
0.65

6.
The limiting reactant in a reaction
A)
is the reactant for which there is the least amount in grams.
B)
is the reactant which has the lowest coefficient in a balanced equation.
C)
is the reactant for which there is the most amount in grams.
D)
is the reactant for which there is the fewest number of moles.
E)
none of the above

7.
Determine the coefficient for O2 when the following equation is balanced in standard form (smallest whole number integers) C4H10(g) + O2(g) ® CO2(g) + H2O(g)
A)
4
B)
8
C)
10
D)
13
E)
20

8.
For which compound does 0.256 mole weigh 12.8 g?
A)
C2H4O
B)
CO2
C)
CH3Cl
D)
C2H6
E)
none of these

9.
The reaction of 11.9 g of CHCl3 with excess chlorine produced 13.1 g of CCl4, carbon tetrachloride:

What is the percent yield?
A)
100. %
B)
42.7 %