An ideal gas is contained in a container with a volume of 2.50 L at a temperature of 78.0°C and a pressure of 2.00 atm. What is the new volume the gas will occupy when the pressure is reduced to 1.50 atm and temperature is increased to 92.0 °C ? A.3.47 L
B.3.21 L
C.1.95 L
D. 1.80 L
E.2.10 L
Solution:
We can use combined gas law when we are told that either pressure, volume or temperature of an ideal gas changed and are asked to find a new value for one of the variables.
P1V1 = P2V2
n1T1 n2T2
Let's look at the given:
V1= 2.50L
T1 = 78°C +273.15 = 351.15K
P1 = 2.00atm
V2= ?
P2 = 1.5atm
T2 = 92°C +273.15 = 365.15K
The number of moles is staying the same, so we don't have to include n.
2.00atm*2.50L = V2 * 1.5atm
351.15K 365.15K
V2 = 3.466L A