If a sample of gas has a volume of 200 ml at a pressure of 700 mm Hg. What will be its pressure if its volume is reduced to 100 ml?

Meave60
Nov 19, 2015
The new pressure will be
1000 L
, rounded to one significant figure.
Explanation:
Boyle's law states that when a gas is held at a constant temperature and mass in a closed container, the volume and pressure vary inversely. The equation to use is
P
1
V
1
=
P
2
V
2
.
Given
V
1
=
200
mL
×
1
L
1000
mL
=
0.2 L

P
1
=
700 mmHg

V
2
=
100
mL
×
1
L
1000
mL
=
0.1 L

Unknown
P
2

Equation
P
1
V
1
=
P
2
V
2

Solution
Rearrange the equation to isolate
P
2
and solve.
P
2
=
P
1
V
1
V
2

P
2
=
(
700
mmHg
×
0.2
L
)
0.1
L
=
1400 L
, which must be rounded to
1000 L
because all of the measurements have only one significant figure.

The correct answer is c