Question

A mixture of carbon monoxide and carbon dioxide is found to have a density of $1.7\text{g/L}$ at stp(atm). The mole fraction of carbon monoxide is

• A. 0.37
• B. 0.4
• C. 0.22
• D. 0.51

Answer 1

The correct option is A 0.37

$M_{\text{mix}}=\frac{dRT}{P_{\text{mix}}}\Rightarrow M_{\text{mix}}=\frac{1.7\times 0.0821\times 273}{1}=1.7\times 22.4\text{g}$
$M_{\text{mix}}=X_{\text{CO}}\times M_{\text{CO}}+(1-X_{\text{CO}}).M_{C{O}_2}\Rightarrow 38.08=X_{\text{CO}}\times 28+(1-X_{\text{CO}})\times 44\Rightarrow 16X_{\text{CO}}=5.92\Rightarrow X_{\text{CO}}=0.37$