chem help please?

Question

Calculate the pressure exerted by 0.5000 mol N2 in a 10.000 L container at 25.0°C using the van der waals eqn
i got 1.225 atm
what did i do wrong?

Answer 1

(P + a(n/V)^2) (V-nb) = nRT

For N2 I found these values: a = 0.1361 J m^3/mol, b = 3.85×10^-5 m^3/mol. Here we have n = 0.5000 mol, V = 10.000L = 0.010000 m^3 and T = 298K. So we have

(P + 0.1361 (0.5000/0.010000)^2) (0.010000 - 0.5000 (3.85×10^-5)) = 0.5000 (8.314472) (298.0)
so (P + 340.25) (0.009981) = 1238.9
so P + 340.25 = 124124.6
so P = 123784 Pa = 123.78 kPa
= 123.78 / 101.325 atm = 1.222 atm.

So I get the same answer but for the fourth (and last) significant figure; if you rounded off one of the intermediate figures a bit early or used slightly different values for some of the constants that might account for it.

Answer 2

you did it wrong