Question

Which statement about the following reaction is correct?

CaO (s) + H2O (l) yields Ca(OH) 2 (s) deltaH = -65.2 kJ

65.2 kJ of heat is absorbed for every one of CaO that reacts.

130 kJ of heat is released for every mole of H2O that reacts.

32.6 kJ of heat is released for every 0.5 mole of CaO that reacts.

16.3 kJ of heat is absorbed for every 0.5 moles of H2O that reacts.

Answer 1

@bibby please help!!!

Answer 2

@abb0t

Answer 3

the -65.2kJ is the difference of energy between the final minus the initial state of the reaction. In this case is the value for one mole of CaO with one mole of H2O to produce the Ca(OH)2. Because the sign is negative means that the energy in the final state is smaller than in the initial state (the reaction is exothermic). Then the reaction is loosing energy when going from the reactants to the products.
In your options you have some referring to the energy released by one mole and others referring to the energy released by half a mole. Half a mole will absorb or release half of the energy that one mole will need for the same reaction.