[tvtokyo]

A solute has a molar mass of 180 g/mol. Now 36.0 g of this solute is dissolved in 500 mL of water. The density of water is 1.00 g/mL. The density of the solution is 1.11 g/mL. Give the answers in 3 significant figures.

The molarity of the solution is 0.4 mol/L  (mol of solute 36/180 = 0.2) 0.2/(500/1000) = 0.4mol/L
The molality of the solution is  not sure?
The mole fraction of the solute in the solution is ??
The weight percent of the solute in the solution is ??

Please help. Thanks

[Hunter2]

A solute has a molar mass of 180 g/mol. Now 36.0 g of this solute is dissolved in 500 mL of water. The density of water is 1.00 g/mL. The density of the solution is 1.11 g/mL. Give the answers in 3 significant figures.

The molarity of the solution is 0.4 mol/L  (mol of solute 36/180 = 0.2) 0.2/(500/1000) = 0.4mol/L
The molality of the solution is  not sure?
The mole fraction of the solute in the solution is ??
The weight percent of the solute in the solution is ??

Please help. Thanks

What is your own attempt to it?

How is molality defined?  You have the masses given.

[tvtokyo]

Is the mass of solvent 500g (water)
sorry for the mess

[Dan]

Correct: Molality (although your significant figures are not correct and you have no units) and mole fraction.

Molarity and wt% are incorrect because you have assumed that the volume of the solution is 500 mL in your calculations (which it isn't).

So:

What is the total mass of the solution?
So what is the total volume of the solution?

[tvtokyo]

Thanks

Total mass of solution = 36+500= 536g
But total volume I am unsure?

[Hunter2]

What about the specific gravity of the solution  as hint.

[Hunter2]

No. You get total lost. 

You have the weight of water and solute. Gives total weight. You have the specific gravity of the solution, gives your total volume.

[Hunter2]

Yes, but please use units, its a control your calculations are correct or not.