Chapter 12, Problem 21PE

In making candy, a certain recipe calls for heating an aqueous sucrose solution to the “soft- ball" stage, which has a boiling point of $\text{235-240 °F}$. What is the range of mass percentages of the solutions of sugar $\left({\text{C}}_{\text{12}}{\text{H}}_{\text{22}}{\text{O}}_{\text{11}}\right)$ that boil at those two temperatures? (Hint: Remember that molal boiling point elevation constants are in $\text{°C }{m}^{-1}$.)