## A community for students. Sign up today

Here's the question you clicked on:

## anonymous 4 years ago A rock salt (NaCl), ice, and water mixture is used to cool milk and cream to make homemade ice cream. How many grams of rock salt must be added to water to lower the freezing point 16.6°C?

• This Question is Closed
1. Xishem

$\Delta T_f=K_b*m*i$$-16.6K=(1.853\frac{K*kg}{mol})*(\frac{mol(NaCl)}{kg(Sol'n)})*2$$4.479\frac{mol}{K*kg}=\frac{mol_{NaCl}}{kg_{Sol'n}}$From here, no matter what type of simplification I do, I can't seem to eliminate it down to one variable. I think there may not be enough information. I'll keep trying, though.

2. Xishem

This is my best guess, but I'm unsure that it's correct:$\frac{\Delta T_f}{K_b*i}=m$$\frac{-16.6K}{(-1.853\frac{K*kg}{mol})(2)}=m$$m=4.4792\frac{kg}{mol}=4.4792m$$m_{NaCl}=\frac{mols(NaCl)}{kg}$$4.4792m=\frac{mols(NaCl)}{1kg}$$mols(NaCl)=4.4792mol$$4.4792mol(NaCl)*\frac{58.4427g(NaCl)}{1mol(NaCl)}=262g(NaCl)$Once again, I'm not sure about this answer. I'd feel better if someone who knew exactly what they were doing checked it.

3. JFraser

looks good to me, the only thing missing is the mass of water used, but if we assume 1.00kg, then the numbers work out

#### Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy