00:02
In this question we are given this balanced chemical equation and we are told that our heat of reaction, the energy required is 178 kj.
00:13
So that's a positive number.
00:15
So that means this is endothermic.
00:17
In other words, energy goes in.
00:19
So i'm going to write those 178 kj as a reactant.
00:26
So we see from this that for every one mole of caco3 that we want to decompose, it will take 178 kj.
00:38
And i know it's one mole because the coefficient is not written in front of calcium carbonate so it's understood it's a one.
00:45
So i'm essentially using the mole ratio here with the energy.
00:49
So for every one mole of caco3 it requires 178 kj of energy.
00:54
Well we don't have 178 kj of energy, we only have 63 .0...