Question

Calculate the pressure exerted by 18.0 g of N2 in a 700. mL vessel at 298 K using the ideal gas equation. Then, recalculate the pressure using the van der Waals equation. Assuming that the pressure calculated from the van der Waals equation is correct, what is the percent error in the answer when using the ideal gas equation?

Van der Waals constants for N2 are: a= 1.39 atm*L^2/mol^2 , and b=0.0391 L/mol ; R=0.082057 L*atm/K*mol.

Pideal gas law = ____________ atm

Pvan der waals = ____________ atm

Percent error = ___________ %

Thank you! :)

Answer 1

Answer of your 2nd part: - Mass of N_2 = 18.0 g Molar mass of N_2 = 2 times (Molar mass of N) = 2 times (14 g/mol) No. of molar of N_2 (n_N2) = 18.0 g/28 g/mol n_N2 = 0.64 mol volume = 700 ml = 700 times 10^- 3 L volume = 0.7 L and T = -60 degree c T = (- 60 + 273) K T = 213 K and R = 0.082057 L atm/K atm * Acc to ideal gas equation, PV = n_N2 RT P = n_N2 RT/V P = 0.64 mol times 0.082057 L atm/K atm times 213 K/0.7 L P = 15.98 atm or P_ideal gas = 15.98 atm Answer Now r_N2 = 0.64 mol, V = 0.7 L, T = 213 K, R = 0.082057 L atm/K atm a = 1.39 atm L^2/mol^2 and b = 0.0391 L/mol According to vander waal eq^n: - (P + n_N2^2 a/V^2) (V - n_N2 b) = n_N2 RT P = n_N2 RT/V - n_2 b - n^2_N2 a/V^2 put all value in this expression, we get: -