Question

A vessel contain a mixture of 7 g of nitrogen and 11 g of carbondioxide at temperature T = 290 k. If pressure of the mixture is 1 atm $(=1.01\times {10}^{5}N/m^2)$, calculate its density: $(R=8.31J/mol-K)$.

Answer 1

Since the total pressure is 1 atm,

$P=1.01X{10}^5=\frac{290X8.31}{V}(\frac{7}{28}+\frac{11}{44})$

$V=\frac{290X8.31}{1.01X{10}^5}0.5$

$\rho =\frac{m}{V}=\frac{(7+11)\left(1.01X{10}^5\right)}{145X8.31X1000}=1.5kg/m^3$

Answer is $\rho =1.5kg/m^3$