Which statement about the following reaction is correct?

cao (s) + h2o (l) > 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 asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.