Question

Can I please get some Chemistry help?

Answer 1

@AZ @AngeI

Answer 2

A student prepares a solution by dissolving 30.0 grams of urea (CON2H4, 60.056 g/mol) in 36.0 grams of water. What is the mole fraction of water in this solution?

Answer 3

Ok, try this, I used different numbers so that you can actually try it.

Two solutions containing 7.5 grams of urea (CON2H4), and 42.75 grams of a substance X, respectively, in 100 g of hexane, are frozen at the same temperature. Calculate the molecular weight of X.

Mm urea = 60.05 g / mol

1. calculate moles of urea

n = m / Mm

n = 7.5 g / 60.05 g / mol

n = 0.1249 mol of urea


2. calculate mm of X

Mm = m / n

Mm = 42.75 g / 0.1249 mol

Mm = 342.2 g / mol

P.S, I had a question like thisand I found this this so I just copy nad pasted this.

Answer 4

Hope this helps.

Answer 5

Have a nice day.

Answer 6

Katrin, I got 0.014
,

Answer 7

mhmm that's not right. Can you show your work and perhaps we can see where you went wrong :)

Mole fraction = moles solvent / moles of solution

Answer 8

So first find the moles of water

Then the moles of urea

mole fraction of water = moles of water / (moles of water + moles of urea)

Answer 9

I did 30/60.056/36