Question

The degree of dissociation is 0.4 at 400 K and 1.0 atm for the gaseous reaction $PC{l}_5\rightleftharpoons PC{l}_3+C{l}_2$. Assuming ideal behaviour of all gases, calculate the density of equilibrium mixture at 400 K and 1.0 atmosphere. (Relative atomic mass of $P=31.0$ and $Cl=35.5$)

• A. 4.60 g/litre
• B. 4.53 g/litre
• C. 4.75 litre
• D. 4.35 litre

Answer 1

The correct option is B 4.53 g/litre

$PC{l}_5\rightleftharpoons PC{l}_3+C{l}_2$

Initialmoles $100$

Moles at equilibrium $1-0.40.40.4$

Total moles $=1.4$ $\{Exp.molwtofPC{l}_5=\frac{208.5}{1.4}\}$

$PV=W/m\times RT$

$PM=dRT$

$d=1\times \frac{208.5}{1.4\times 0.082\times 400}$

$=4.53g/lit$