Question

Given two processes:
`(1)/(2)P_(4)(s) +3CI_(2)(g) rarr 2PCI_(3)(l), DeltaH =- 635 kJ`
`PCI_(3) (l) +CI_(2)(g) rarrPCI_(5)(s), DeltaH =- 137 kJ` The value of `DeltaH^(Theta)` of `PCI_(5)` is
A. `454.5kJ" "mol^(-1)`
B. `-454.5kJ`
C. `-772kJ" "mol^(-1)`
D. `-498kJ" "mol^(-1)`

Answer 1

Correct Answer - B
`(1)/(4)P_(4)(s)+(3)/(2)Cl_(2)(g)toPCl_(5)(l),DeltaH=-(635)/(2)kJ`
`PCl_(3)(l)+Cl_(g)toPCl_(5)(s),DeltaH=-137kJ`
On adding, `overline((1)/(4)P_(4)(s)+(5)/(2)Cl_(2)(g)toPCl_(5)(s),DeltaH=-137kJ)`