00:01
If we look closely at the figures, we see that from a to b, we are having separation of water.
00:17
This requires energy to pull the water molecules apart to make room for the solute.
00:23
Then when we go from b to c, we have separation of the sodium bromide, which also requires energy.
00:35
Last of all, we go from c to d where we have formation of solution.
00:42
This is the only change that is exothermic where heat is released.
00:47
The first two are endothermic and require heat.
00:55
The enthalpy of solution they state is negative when sodium bromide dissolves.
01:01
Use this information to list the stages in order of increasing enthalpy.
01:08
If delta h solution is negative, delta h solution is delta h for process a to b plus delta h for process b to c and plus the delta h for the process c to d.
01:38
Both of these are positive so this sum needs to be less than the delta h cd...