Calculate the volume of the gas, in liters, if 1.75 mol has a pressure of 1.20 atm at a temperature of -7 ∘C. Express the volume in liters to three significant digits.

Question

I need help on how to set this problem up.

Answer 1

Hey Abril!

So it looks to me like this is an ideal gas problem, thus we will need to use the ideal gas equation.

PV=nRT

R= 0.0821 L •atm/K•mol

We're looking for the volume, V, in liters but let's see what other variables we have for this equation.

We're given :

Pressure, P= 1.20atm

Moles, n= 1.75 moles

We have the R constant = 0.0821

Temperature, T = -7°C. We must convert this to Kelvin in order to work with the R constant. 273K = 0°C thus -7°C = 273-7 = 266K

Since we have all the other variables of the equation other than V, we can plug these in and just solve for V.

PV=nRT

1.2atm(V) = 1.75 moles(0.0821 L •atm/K•mol)(266K)

1.2atm(V) = 38.2L•atm ... remember we're keeping 3 sig figs

V= 31.8L