Chemistry Reference
In-Depth Information
EXAMPLE 10.11
Calculate the number of moles of solid mercury(I) oxide that can be produced
by the reaction of oxygen gas with 25.0 mL of liquid mercury
Also, calculate the number of molecules of oxygen required.
(density
13.6 g/mL).
Solution
4 Hg(
/
)
O
2
(g) £ 2 Hg
2
O(s)
a
13.6 g Hg
1 mL Hg
a
1 mol Hg
200.6 g Hg
a
2 mol Hg
2
O
4 mol Hg
25.0 mL Hg
b
b
b
0.847 mol Hg
2
O
Moles
of Hg
2
O
and of O
2
Balanced
chemical
equation
Milliliters
of Hg
Grams
of Hg
Molar
mass
Moles
of Hg
Avogadro's
number
Molecules
of O
2
Density
10
23
molecules O
2
1 mol O
2
a
13.6 g Hg
1 mL Hg
ba
1 mol Hg
200.6 g Hg
ba
1 mol O
2
4 mol Hg
ba
6.02
25.0 mL Hg
b
10
23
molecules O
2
2.55
Practice Problem 10.11
Calculate the volume of liquid water
produced by burning 48.4 g of propane gas,
(density
1.00 g/mL)
C
3
H
8
,
and
condensing the gaseous water produced.
EXAMPLE 10.12
(a)
A girl takes 444 pennies from her piggy bank to buy jelly beans, which
cost $3.30 per pound. If there are 110 jelly beans per pound, how many
jelly beans can she buy?
(b)
How many
O
2
molecules does it take to produce 425 mmol of
H
2
O
by a
combination reaction with sufficient
H
2
gas?
Solution
(a)
Number of
jelly beans
Definition
of cent
Price per
pound
Number
per pound
Cents
Dollars
Pounds
a
110 jelly beans
1 lb
a
1 dollar
100 cents
1.00 lb
3.30 dollars
444 cents
b
a
b
b
148 jelly beans
