1. Which compound in each pair has a higher melting or boiling point? Explain.

a. MgO or NaCI (melt)

b. HBr or Kr (boil)

c. CaBr, or CaCli(melt)

d. SiH, or PH, (boil)

2. The molar heat of vaporization for benzene (C61-16) is 7.3kcal/mol. How many calories are required to vaporize 425g of benzene at its boiling point?

3. What is the heat of vaporization of a liquid if 215mol of the liquid required 2040) of energy to vaporize at its boiling point?

4. The molar heat of vaporization for carbon tetrachloride is 29.50Wmol. What mass of CCI, can be vaporized at its boiling point by the addition of 650.0?