Saved Bookmarks
| 1. |
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 iceA. `+1622` kJB. `-1622 ` kJC. `+292` kJD. `-292`kJ |
|
Answer» Correct Answer - B (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` |
|