Given : `S_((s))+(3)/(2)O_(2(g))rarrSO_(3(g)+2X Kcal`
`SO_(2(s))+(1)/(2)O_(2(g))rarrSO_(3(g)+Y Kcal`
The heat of formation of `SO_(2)` is `:-`

Options

A. (2x + y)
B. `-(2x - y)`
C. x + y
D. 2x / y

Answer

B

Explanation

(i) `S_((s))+(3)/(2)O_(2(g))rarr SO_(3(g)) , Delta H=-2x KCal`
(ii) `SO_(2(g))+(1)/(2)O_(2)(g)rarr SO_(2(g)) , Delta H = -y KCal`
`S_((s))+O_(2(g))rarr SO_(2(g)) , Delta H_(f) = ?`
Desired equation = eq(i)-eq(ii)
`Delta H_(f)=-2x-(-y)=(-2x-y)`