00:03
We're asked to use the values in appendix 4 to calculate the delta h for each of the following reactions to calculate the delta h knot.
00:12
We're going to take the delta h not a formation for the products, and we're going to subtract the delta h knot formation for the reactants.
00:25
For a, we're given this in terms of a diagram, so a represents in a chemical equation 2nh3, add 302 and 2c4 to produce 2hcn and 6h2o.
00:55
The delta h reaction is equal to delta h formation for the h2o plus 2 delta h formation for the hcn minus 2 delta h formation the n h 3 plus 3 delta h formation the o 2 plus 2 delta h formation of the ch 4 plug in our values here and we're going to leave out the units units are kilojoules per mole we'll have 6 .92 plus 235 .1 minus 2, negative 46, 3 ,0 plus 2, negative 75 .5.
02:33
And solving this here would give me delta -h reaction of negative 900, negative 939 .2.
02:41
Eight kilojoules per mole for the reaction given in part a.
02:49
The reaction given in part b is given to us as a chemical reaction so the delta h not would be equal to the anthopy of the and the formation of the products.
03:07
So 2 delta h times delta h formation of h3 -p -o -4 plus 3 delta h not formation of calcium sulfate minus the delta h.
03:46
Knot of formation of calcium phosphate plus three times the delta h.
03:56
Not a formation of h2s .o4.
04:03
And let's go ahead and find these numbers here...
