Question

45 g of ethylene glycol is mixed with 600 g of water. What is the freezing point of the solution? $(k_f=1.86Kkgmo{l}^{-1})$

• A. $-270.90K$
• B. $270.90K$
• C. $273K$
• D. $274.15K$
• E. $-274.15K$

Answer 1

Answer: (B)

$\Delta T_f=\frac{k_f\times w_B\times 1000}{w_A\times w_B}$ $w_A=600g,w_B=45g,k_f=1.86Kkgmo{l}^{-1}$ $M_B=62gmo{l}^{-1}$ $\therefore$ $\Delta T_f=\frac{1.86\times 45\times 1000}{600\times 62}=2.25K$ Hence, freezing point of aqueous solution $=273.15-2.25$ $=270.90K$