Answer
4.879 atm
Work Step by Step
We have a 35.1g sample of CO2 so we convert this to moles. First we need the molar mass of CO2 as follows:
Carbon is 12g/mol, O is 16g/mol
12 + 2*16 = 44g/mol
35.1g * (1mol/44g) = 0.798 moles
The sample is placed in a 4L container and heated to 298K so we would have:
PV = nRT or P = nRT/V = (0.798 mol * 0.0821 * 298K) / 4L = 4.879 atm