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?

1 Answer
Nov 19, 2015

Answer:

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_1V_1=P_2V_2#.

Given
#V_1=200cancel"mL"xx(1"L")/(1000cancel"mL")="0.2 L"#
#P_1="700 mmHg"#
#V_2=100cancel"mL"xx(1"L")/(1000cancel"mL")="0.1 L"#

Unknown
#P_2#

Equation
#P_1V_1=P_2V_2#

Solution
Rearrange the equation to isolate #P_2# and solve.

#P_2=(P_1V_1)/(V_2)#

#P_2=((700"mmHg"xx0.2cancel"L"))/(0.1cancel"L")="1400 L"#, which must be rounded to #"1000 L"# because all of the measurements have only one significant figure.