00:01
We have four questions to answer our first question.
00:03
Five grams of sugar are dissolved in water.
00:06
What happens to the boiling point? oh, the boiling point will decrease.
00:27
Boiling point? no, the boiling point will increase.
00:44
Yes, boiling point will increase initially, then decrease over time, and it will have no effect.
01:13
So my answer was the boiling point will increase.
01:30
Second question, four, compute the boiling point constant in degrees c per molality.
01:57
Given our delta t is 3 .5 degrees c, we have 2 .5 molal, three sig figs, no units.
02:29
Dang it.
02:33
We've got a software update.
02:34
It keeps asking me, but i'm always using my computer.
02:40
Okay, so what we'll have is our delta t equal our kb times our molality times i.
02:51
I equals 1.
02:53
So i will have 3 .5 degrees c equals the kb times our molality times i, which is 1.
03:07
So our kb will equal 3 .5 divided by 2 .5, 1 .40, 3 sig figs.
03:30
That's a cheat we should enter, and we know that's degrees c molality.
03:38
And next, how much does the boiling point increase? given 240 grams of a non -electrolyte with a molar weight of 342 grams per mole in 850 grams of h2o.
04:27
Our kb is 0 .512.
04:32
Three sig figs, no units.
04:45
Okay, hey, so on this one, we're calculating delta t.
04:51
That will equal 0 .512 times my molality, which will be 240 grams and 342 grams per mole.
05:13
This whole thing divided by 0 .850 kilograms times 1.
05:24
0 .512 times 240 divided by 342 divided by 0 .85.
05:39
I have a log in there...