00:01
To calculate the molality that's fructose, we need to know the moles of fructose and the kilogram of the solvent.
00:08
To calculate the moles of fructose, we'll take the mass of fructose, 24 grams, and divide by its molar mass.
00:15
Then we'll divide that by the kilograms, 1, of water, and we get a molality of 1, or 0 .133 molal fructose.
00:24
Next, to get mole fraction, we'll take the moles of fructose, which again will be the mass divided by the molar mass, divide that whole thing by the total moles, which again will be the moles of fructose plus the moles of water.
00:39
There's one kilogram of water, so it's 1 ,000 grams of water, which we divide by the molar mass of water to get the moles of water.
00:47
This then gives us a mole fraction fructose of 2 .39 times 10 to the negative 3.
00:55
Now to get the mass fraction, i'm sorry, the mass percent, it's going to be the mass fructose, 24 grams, divided by the total mass, which will be the 24 plus the 1 ,000 of water...