Assuming enthalpy of combustion of hydrogen at 273 K is -286 kJ and enthalpy of fusion of ice at the same temperature to be `+6.0` kJ , calculate enthalpy change during formation of 100 g of ice

Options

A. `+1622` kJ
B. `-1622 ` kJ
C. `+292` kJ
D. `-292`kJ

Answer

B

Explanation

(i) `H_(2) (g) + (1)/(2) O_(2) (g) to H_(2)O(l) , Delta_e H = -286 kJ`
(II) `H_(2) O (s) to underset(18 g) (H_(2)O) (l) , Delta _("fus") H = + 6 kJ`
On substaracting (II) from (I)
`H_(2) (g) + (1)/(2) O_(2) (g) to H_(2)O (s)`
`Delta H = - 286 - 6 = - 292 kJ`
`because` On formation of 18 g ice , change in enthalpy
= -292 kJ
`therefore` On formation of 100 g ice , change in enthalpy
`= - (292 xx 100)/(18) = - 1622 k J`