Chem Turn in Lab from yesterday Work on the vapor pressure and intermolecular forces review on the front of today’s packet

Intermolecular Forces Forces of attraction between molecules (dotted lines represents attraction between molecules)

Provide an explanation as to why the following phenomena occur: Water beads up on your windshield, but acetone doesn't. (Relate IMFs and Surface Tension) Water is less viscous than molasses (Relate IMFs and Viscosity) Molecular nitrogen boils at 77 K, while nitric oxide boils at 110 K. (Relate IMFs and Boiling Point) A test tube was filled halfway with acetone and another was filled halfway with water. Both test tubes are left at room temperature. A few hours later, much of the acetone had evaporated while most of the water was still in the test tube. (Relate IMFs and Volatility). Butane is a gas at standard temperature and pressure while pentane is a liquid. (Relate IMFs and state of matter) Explain how the demo worked by relating IMFs, vapor pressure, and boiling point. Water has stronger intermolecular forces between its molecules than acetone

As you increase the temperature of the liquid, the liquid particles move faster. The vapor pressure also increases, eventually allowing the liquid to boil

Phase Diagram

Phase Diagrams Triple point (T) The pressure and temperature at which all three states of matter are in equilibrium and coexist. Critical Point (C) The highest pressure and temperature in which the liquid and gas can coexist. (it is impossible to liquefy the gas above this temperature no matter what the pressure is)

Normal Melting and Boiling Point Occurs at standard pressure (1 atm)!