According to equation, `C_(6)H_(6)(l)+15//2 O_(2)(g)rarr 6CO_(2)(g)+3H_(2)O(l), Delta H= -3264.4 "KJ mol"^(-1)` the energy evolved when 7.8 g benzene is burnt in air will be -

Options

A. `- 326.4 kJ//mol `
B. 326.4 kJ//mol
C. 32.64 kJ //mol
D. 3.264 kJ//mol

Answer

B

Explanation

For 1 mole = 78 g `rArr Delta H =- 3264.4 kJ`
`therefore Delta H " per " 7.8 g = (-3264.4 xx 7.8)/(78) =- 326.4 kJ`
Heat evolved = 326. kJ `(Delta H = -326. kJ)`