Colligative Properties Part 1 Student Learning Objectives 1. Review the relationships among molecular structure, intermolecular forces, and physical properties. 2. to analyze the types and relative strengths of intermolecular forces in a solution, with the goal of predicting whether two substances will form a solution or not. 3. to recognize the roles of enthalpic and entropic considerations underlying the "like dissolves like" rule. 4. to understand the colligative properties of a solution vs pure solvent. (Freezing point)

Over the past weekend, the Northeast was blasted by a terrible winter storm. We received about 4-6 inches of snow. Temperatures on Sunday morning were as low as 8oF in Dover, Delaware. Tysean, Lauren, and Roger decided to brave the weather and pick up snacks for the Chiefs and Bengals game at 3pm. After clearing Tyseans car of snow and ice, they got in and tried to start the vehicle. The engine hesitated for a while, but eventually turned over. When the car finally started, it ran roughly, gurgling and chugging. It sounds like its not getting enough gas, Roger stated. When was the last time you added dry gas? Whats that? Tysean responded. Its the stuff you add to the gas tank to keep the fuel line from freezing Lauren said. Im confused. Tysean said. Gasoline doesnt freeze at this temperature, does it? I dont know, it might have something to do with gas getting wet Roger replied. It has always worked for me in the winter Oh wow. Lets grab some from Wawa when we go to grab these snacks Tysean responded. Great, you owe me a hot latte, anyway. My hands are freezing! Lauren said.

Questions: 1. Draw the structural formula for gasoline. 2. What is the freezing point of water? What is the freezing point of gasoline? 3. Suppose water got into the fuel line, how would water and gasoline interact? 4. Will the presence of water affect the freezing point of gasoline? Explain. 5. What is the main ingredient in dry gas? How would this ingredient affect the gas-water system?