Stoichiometry
1. What is the mass of one mole of acetylsalicylic acid (aspirin), C
9
H
8
O
4
?
a.
29 g
b.
108 g
c.
196 g
d.
180. g
e.
none of the above
2. Determine the number of moles of aluminum in 2.154 x 10
-1
kg of Al.
a.
5816 mol
b.
7.984 mol
c.
6.02 x 10
23
mol
d.
4.801 mol
e.
8.783 mol
3. How many grams of zinc are there in 22.7 g of ZnCl
2
?
a.
0.35 g
b.
0.17 g
c.
10.9 g
d.
1476 g
e.
0.32 g
4. A compound with a composition of 87.5 % N and 12.5 % H was recently discovered.
What is the empirical formula for this compound?
a.
NH
2
b.
N
2
H
3
c.
NH
d.
N
2
H
2
e.
N
2
H
5. This equation is unbalanced: PCl
3
+ H
2
O
→
H
3
PO
3
+ HCl When it is correctly
balanced, the coefficients are, respectively
a.
1,3,1,1
b.
1,1,1,3
c.
1,3,1,3
d.
2,3,2,3
e.
none of the above