Question

A sample of an ideal gas has a volume of 2.39 L at 279 K and 1.06 atm. Calculate the pressure when the volume is 1.80 L and the temperature is 302 K.

____atm

Answer 1

For an ideal gas, the equation is expressed as

PV = nRT

where
P = pressure = 1.06 atm
V = volume = 2.39 L
n = number of moles = ?
R = gas constant =  0.082 L atm mol^-1 K^-1
T = temperature = 279 K

Now, substituting the values in the ideal gas equation, we get

PV = nRT

(1.06 atm) (2.39 L) = n (0.082 L atm mol^-1 K^-1) (279 K)

n = [ (1.06 atm) (2.39 L) ] / [ (0.082 L atm mol^-1 K^-1) (279 K) ]

n = 0.11 mol

Now, the pressure when the volume is 1.80 L and the temperature is 302 K.

Number of moles will not change, so n = 0.11 mol

Again,

PV = n R T

P = n R T / V
= [ (0.11 mol) (0.082 L atm mol^-1 K^-1) (302 K) ] / (1.80 L)
= 1.51 atm