# Question #7b124

##### 1 Answer

The solution should contain 21 % sucrose by mass.

This is really two problems: (a) What molality of solution will give the observed boiling point? (b) What is the percent composition of this solution?

**Step 1.** Calculate the molality of the solution.

**Step 2.** Calculate the percent composition.

Moles of sucrose = 0.78 mol sucrose ×

So you have 270 g sucrose in 1 kg water.

% by mass =