Reference no: EM132753758

1. Adter exercising on a hot summer day and working up a sweat, you often become cool when you stop. What is the molecular-level explanation of this phenomenon?

2. The chlorofluorocarbon CCl3F has an enthalpy of vaporization of 24.8 kJ/mol. To vaporize 1.00 kg of the compound, how much thermal energy transfer is required?

3. The molar enthalphy of vaporization of methanol is 38.0 kJ/mol at 25Celcius. How much thermal energy transfer is required to convert 250. ml of alcohol from liquid to vapor? The density of CH3OH is 0.787 g/mL at 25Celcius.

4. Briefly explain the variations in the boiling point below. In ur discussion be sure to mention the types of intermolecular forces involved
COMPOUND BOILING POINT

NH3 -33.4
PH3 -87.5
AsH3 -62.4
SbH3 -18.4

5. Methanol, CH3OH, has a normal boiling point of 64.7 C and a vapor pressure of 100 mm Hg at 21.2 C. Formaldehyde, H2C=O, has a normal boiling point of -19.5 C and a vapor pressure of 100 mm Hg at -57.3 C. Explain why these two compounds have different boiling points and require different temperatures to achieve the same vapor pressure.