Answer:
[tex]\large \boxed{\text{2.55 mol/kg}}[/tex]
Explanation:
1.Calculate the freezing point depression
ΔTf = 0.00 °C - (-4.75 °C) = = 0.00 °C + 4.75 °C = 4.75 °C
2. Calculate the molal concentration
The formula for the freezing point depression by a nonelectrolyte is
[tex]\Delta T_{f} = K_{f}b\\b = \dfrac{\Delta T_{f}}{ K_{f}} = \dfrac{4.75 \, ^{\circ}\text{C}}{\text{1.86 $\, ^{\circ}$C$\cdot$kg$\cdot$mol}^{-1}} = \textbf{2.55 mol/kg}\\\\\text{The molal concentration of sucrose is $\large \boxed{\textbf{2.55 mol/kg}}$}[/tex]
