00:01
Okay, so we need to calculate the freezing point of an ethylene glycol solution, which is c2h602.
00:11
We're told that we have 21 .2 grams of that, and we're also told that we have 85 .4 milliliters of water.
00:23
And we want to calculate the new freezing temperature of the substance.
00:30
Now to do that, we're going to have to use the equation the change in freezing temperature is equal to the freezing point depression constant times the molality times the vantt -hop factor, or the number of particles this breaks into.
00:49
And since ethylene glycol is covalent, i is equal to 1.
00:53
It doesn't break up into any pieces.
00:56
We're told that the constant is 1 .86 degrees.
01:01
See per molal and since the temperature is going to drop we can make that negative and we have to calculate the molality so we're going to use our values of grams and milliliters to calculate our molality so molality is moles of solute our solute is our ethylene glycol over kilograms of solvent which is our water so the first thing we need to do is convert grams of our ethylene glycol into molds.
01:43
So we're going to have to calculate the molar mass of our ethylene glycol.
01:49
So we're going to have to take two carbons and six hydrogens and two oxygens and add them together.
01:58
And that's 62 .08 grams.
02:01
That is the molar mass of ethylene glycol.
02:04
So if we take our 21 .2 .2 .2 divided by 62 .08, we get 0 .341 moles.
02:13
That is going to go up here as our moles of solute.
02:20
Now, kilograms of solvent, we have 85 .4 milliliters of water...