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The standard enthalpies of formation of ...

The standard enthalpies of formation of HCl(g), H(g) and Cl(g) are `-92.2`, 217.7 and `121.4 kJ mol^(-1)` respectively. The bond dissociation enthalpy of HCl is :

A

`+431.3 kJ`

B

236.9 kJ

C

`-431.3 kJ`

D

339.1 kJ

Text Solution

Verified by Experts

The correct Answer is:
A
`HCl(g) lt H(g) + Cl(g)`
`Delta H = [Delta_(f)H(H(g)) + Delta_(f)H Cl(g)] - Delta_(f)H (HCl(g))`
`= 217.7 + 121.4 - (- 92.2) = 431.3 kJ`
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