Suppose that 13g of a nonelectrolyte is dissolved in 0.50 kg of benzene. The boiling point of this solution is 80.61 °C. The normal boiling point of benzene is
80.10 °C. The molal boiling point elevation constant for benzene is 2.53 °C/m. What is the
molar mass of the solute?

The answer for this question is d. none of these

What do you not know about it

Ibelieve it's temperature! i'm not 100% sure.

Answer is:     molar solubility of  yttrium fluorid is 4.23·10⁻⁶ m. balanced chemical reaction: yf₃(s)  → y³⁺(aq) + 3f⁻(aq). ksp = 8.62·10⁻²¹. ksp = [y³⁺]  · [f⁻]³.[y³⁺] = [yf₃] = s.[f⁻] = 3[yf₃] = 3s.ksp(yf₃)  = s  · (3s)³.8.62·10⁻²¹ = 27s⁴.s(yf₃)  =  ⁴√(8.62·10⁻²¹  ÷ 27).s(yf₃)  = 0.00000423 m.s(yf₃) = 4.23·10⁻⁶ m.