Answer
a. 22.8 cubic meters.
b. $2.15\times10^5\;Pa$.
Work Step by Step
a. Find the number of moles of nitrogen in 28.5 kg.
$$n=\frac{28.5\;kg}{28.0\times10^{-3}kg/mol}=1018\;mol$$
Use the ideal gas model for nitrogen to calculate the volume of the gas.
$$V=\frac{nRT}{P}=\frac{(1018\;mol)(8.314)(273\;K)}{1.013\times10^5\;Pa}\approx 22.8\;m^3$$
b. Find the new number of moles.
$$n=\frac{28.5+32.2\;kg}{28.0\times10^{-3}kg/mol}=2168\;mol$$
Use the ideal gas model for nitrogen to calculate the pressure of the gas.
$$P=\frac{nRT}{V}=\frac{(2168\;mol)(8.314)(273\;K)}{22.8\;m^3 }\approx 2.15\times10^5\;Pa $$