00:01
Continuing on with solution chemistry here we are looking at the heat of hydration and this is defined as the heat that is evolved or absorbed when hydration occurs so what we have is the following reaction so we have n a c l is a solid we get n a plus there's a gas and c l minus where h -0 is equal to 787 kilojoules per mole and so therefore we have an a plus as a gas, add cl minus as a gas, and we get nacl as the solid, where the h -0 is 7 -9 -7 -87 kilojoules per mole.
00:54
And finally, we can add these together with the second equation, where we have n -a -c -l as a solid, and that involves the following.
01:14
N -a -plus in aqueous conditions, add c -l -minus in aqueous conditions.
01:20
The h -0 is equal to 4 kilojoules per mole.
01:24
So we add the first and the second equation that i've just labelled.
01:29
And so what we get is n -a -plus as a gas, add c -l -minus as a gas.
01:36
We get n -a -plus aqueous, add c -l -m -aquius.
01:44
And so we get the following value that is negative 7 .8 .3 kilojoules per mole...