Consider the reaction,
`4NO_(2)(g)+O_(2)(g)rarr2N_(2)O_(5)(g),Delta_(r )H=-111 kJ.` If `N_(2)O_(5)(s)` is formed instead of `N_(2)O_(5)(g)` in the above reaction, the `Delta_(r )H` value will be
(Given, `DeltaH` of sublimation for `N_(2)O_(5)` is `54 kJ mol^(-1))`

Options

A. ` -165 kJ `
B. `+ 54 kJ `
C. `+219kJ`
D. ` -219kJ `

Answer

A

Explanation

By Hess's law `Delta H +54 =- 111 kJ`
or `Delta H =-165 kJ`