00:01
Okay, to solve this, we are going to start with our equation.
00:06
E equals hv, and we also have another equation c equals lambda v.
00:13
So our lambda is our wavelength.
00:17
I'm just going to want to wave.
00:20
V stands for frequency.
00:29
Again, this would be frequency, and then h is planck's constant, which is 6 .6.
00:38
Times 10 to the negative 34.
00:43
Great.
00:44
So we want to rearrange e in order to have our wavelength in it.
00:49
So if we first rearrange this equation, oh, and c is the speed of light.
00:53
I'll just put sl, speed of light.
00:57
So we know that wavelength equals c divided by v.
01:10
Oh, you know what? excuse me, i just did something.
01:17
This is a better way to explain it.
01:18
Okay, we know that v equals c over wavelength.
01:28
And now we can go ahead and plug this v into our equation right here, and we will get e equals hc over wavelength.
01:41
You can also just memorize e equals hc over wavelength, but i think it's always helpful to kind of see where you would derive that.
01:48
Okay, so for the first one, we have 90 .5 kilojoules per mole.
01:59
So first we want to make sure we put everything into jewels.
02:03
So to do that, we're just going to multiply this by a thousand.
02:08
That'll give us jewels.
02:11
And then this is our energy, so it's going to be equal to planks, constant.
02:18
So 6 .6 times 10 to the negative 34th.
02:27
Great.
02:28
And then we have our speed of light, which is 3 times 10 to the 8th.
02:33
That's always something you should memorize.
02:37
And then in order to get rid of this moles, we want to multiply this by apagodro's number, which is 6 .02 times times 10 to the 23rd.
02:52
And i'm leaving my units out, but it's always good practice to put your units in as well.
02:58
And then we're going to have our wavelength here.
03:02
So again, this is just plugging in what we already know to this equation up here.
03:09
So if you go ahead and solve for that, you will find that wavelength equals 1 .32 times 10 to the negative 6 meters.
03:33
All right.
03:33
And then in order to find what this would correspond to in the electromagnetic spectrum, we had that here.
03:41
So we're going to find 10 to the negative 6th, which is right here...