Question

1. How many grams of ethylene glycol, C2H4(OH)2, are needed per kilogram of water to protect radiator fluid against freezing down to -10°C?

2. For benzene, C6H6, the freezing point constant, Kf, is 5.12 K oC/m and its normal freezing point is 5.5°C. What is the freezing point of a solution containing 100.0 g of benzene and 20.0 g of naphthalene (C10H8)?

3. When 5.0 g of an unknown substance is dissolved in 100.0 g of water, the freezing point of the solution decreases by 1.5°C. What is the molar mass of the unknown substance if the compound does not dissociate to form ions in solution?

4. If 2.00 moles of a substance is dissolved in 1.00 kg of water, the freezing point of the solution decreases by 7.44°C. Does this substance dissociate to form ions in solution? Explain why.

5. Calculate the freezing point of a 0.2 m CaCl2 aqueous solution, assuming it dissociates completely to form ions in solution.