Urea is a common fertilizer with the formula CO(NH2)2 that is sometimes used as a chemical de-icer for icy road surfaces in the winter months. Adding a solute to a solvent causes the freezing point to be lowered and allows the solvent to remain liquid at lower temperatures. The value of Kf for water is 1.86°C/m, and its normal freezing point is 0.00°C. Urea is a nonvolatile nonelectrolyte solute. What molality of urea is required to lower the freezing point of ice water by 1.13°C?

Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. an industrial chemist studying this reaction fills a 25.0l tank with 4.5 mol of sulfur dioxide gas and 4.5 mol of oxygen gas at 30.°c. he then raises the temperature, and when the mixture has come to equilibrium measures the amount of sulfur trioxide gas to be 1.4 mol. calculate the concentration equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. round your answer to 2 significant digits.