Question

4 moles of $PC{l}_5$ are heated at constant temperature in closed container. If degree of dissociation for $PC{l}_5$ is 0.5 calculate total number of moles at equilibrium

• A. 6
• B. 4.5
• C. 3
• D. 5.5

Answer 1

The correct option is B 4.5

${PCl}_5\rightleftharpoons {PCl}_3+{Cl}_{2}Initialconc:AtEquilibrium:{PCl}_5=4{PCl}_5=4-\alpha =4-0.5{PCl}_3=0{PCl}_3=0.5{Cl}_2=0{Cl}_2=0.5Totalmoles=4-0.5+0.5+0.5=4.5$