Carbon monoxide reacts with hydrogen gas to produce a...

Carbon monoxide reacts with hydrogen gas to produce a mixture of methane, carbon dioxide, and water. (This mixture is known as substitute natural gas.) 4CO(g) + 8H2(g) ? 3CH4(g) + CO2(g) + 2H2O(?) Use the following thermochemical equations to determine the enthalpy change of the reaction. C(graphite) + 2H2(g) ? CH4(g) + 74.8 kJ CO(g) + 1/2 O2(g) ? CO2(g) + 283.1 kJ H2(g) + 1/2 O2(g) ? H2O(g) + 241.8 kJ C(graphite) + 1/2 O2(g) ? CO(g) + 110.5 kJ H2O(?) + 44.0 kJ ? H2O(g)

Transcript

00:01 Okay, so for this question, we are using hess's law of summation.

00:04 And the blue equation at the top is what we're trying to get all of these black equations to add up to.

00:10 So we need to manipulate these black equations so that they match up with the blue one.

00:17 So i'm going to start with the...

00:26 It's kind of strange, but okay, i'll start with what i did here.

00:29 So you have these equations that were written out in the prompt.

00:32 And it had like plus, for this first one, plus 74 .8.

00:36 It was a product, which means that heat was given off.

00:39 So it's actually a negative 74 .8.

00:42 All of them had that plus some number of kilojoules on the right side, except this last one where it was on the left, which means it's endothermic, meaning it's positive.

00:53 Positive okay so um i am going to not start with the co because i have co in a couple of different places and i don't know for sure which one i need to use where so i'm going to start with um the h2 oh so i can do that okay so h2 needs to be on the left and we oh no no ch4 i only have have ch4 in one place.

01:24 Sorry.

01:25 Ch4 needs to be on the right.

01:26 So i'm going to go ahead and put, i'm going to copy, recopy down this first black equation here, and i'm going to multiply it by three because i have to have three ch4s in the product.

01:39 So three c graphite, the rest are all gases except for this liquid water at the bottom.

01:46 And then this will become 6h2 goes to 3ch4.

01:54 And then i need to multiply this 74 .8, negative 74 .8 by 3.

02:03 So that becomes negative 224 .4.

02:07 And then i'm crossing that off because i'm done with that equation.

02:11 I can't use it again.

02:12 All right, the next thing i need to do is get rid of three graphites because i know there's no graphite in there.

02:18 And i have that right here.

02:19 So i'm going to flip this reaction and multiply it by three.

02:24 So i will have three co on the left goes to three carbon graphites plus one and a half oxygens...

Question

Please give Ace some feedback