00:01
We are asked to find the ch bond energy.
00:10
To find the average ch bond in ethane, what are we given here? we're given that in methane, the ch bond energy is 415 kilojoules per mole.
00:40
So we're supposed to do three here.
00:42
Our first one is ethane, ethane c2h6, and our c -c bond.
01:00
It's a little hard to read.
01:05
Okay, i'm going to write this down.
01:22
And we're told that my heat of reaction is negative 65 .07.
01:33
That's kilojoules per mole.
01:37
Okay, we can do this one.
01:42
So my heat of reaction will equal my sum of my bonds broken, the sums of my bond energy of bonds broken, minus the sum of my bonds formed.
02:23
Okay, so my ch bond will denote as x.
02:33
And on my left side, i have 1, 2, 3, 4, 5, 6.
02:39
For c2h6, i have six ch bonds, which will be 6x.
02:50
And i have one c -c bond, and i have one h -h bond.
02:59
So i'll add all these together, and we will subtract from that 2ch4, 2 times 4x.
03:25
Now, for methane, we will just use our 415.
03:42
But did it say average ch bond? okay, that'll be eight times that.
03:52
This is my ch4.
03:53
Okay, let me get my calculator out.
03:58
So we were told that our heat of reaction is negative 65 .02, and that will equal 6x plus my 347 plus 432 minus what is eight times 415 is 3320.
05:03
So my 6x will equal 2475 .98x equals 412 .0 kilojoules per mole.
05:25
So my ch bond in ethane is approximately equal to 400.
05:34
Was i given here? 413 kilojoules per mole.
05:52
Next, let's do ethane.
05:57
So we're going to do c -c -c2h4.
06:09
So c2h4, we're given our heat of reaction is negative 202 .21 kilojoules per mole.
06:23
This is given...