Question

What is the freezing point of a solution of ethyl alcohol, that contains 24.3 g of the solute (C2H5OH), dissolved in 540 g of water?

Answer 1

What is the freezing point of a solution of ethyl alcohol, that contains 24.3 g of the solute (C2H5OH), dissolved in 540 g of water?

$$\mathrm {T} = \mathrm {K} ^ {*} \mathrm {C} _ {\mathrm {M}}$$ $$C _ {M} = \frac {\nu \left(C _ {2} H _ {5} O H\right)}{m \left(C _ {2} H _ {5} O H\right) + m \left(H _ {2} O\right)}$$ C _ {M} = \frac {\frac {m \left(C _ {2} H _ {5} O H\right) ^ {* 1 0 0 0}}{M \left(C _ {2} H _ {5} O H\right)} m \left(H _ {2} O\right)} $$C _ {M} = \frac {\frac {2 4 , 3 * 1 0 0 0}{4 6}}{5 4 0} = 0. 9 8 m o l ^ {*} k g ^ {- 1}$$ $$\Delta T = (1, 8 6 K ^ {*} k g ^ {*} m o l ^ {- 1}) ^ {*} (0. 9 8 ^ {*} m o l ^ {*} k g ^ {- 1}) = 1, 8 3 K$$ $$T = T _ {0} - \Delta T$$ $$T = 2 7 3 K - 1, 8 3 K = 2 7 1, 1 7 K$$ $$t = 2 7 1, 1 7 - 2 7 3 K = - 1, 8 3 ^ {\circ} C$$

Answer: T=271,17K t= - 1,83°C