1. Water vapor is invisible.   True   False   2. If 2600 J of energy are expended to rub two ice blocks against each other and the specific latent heat of ice is 325 J/g, then the mass of the melted ice is   8 g   16 g   24 g   32 g   Hint Half-n-half Clue   3. If the specific latent heat of vaporization for water is 2.25 kJ/g, then the amount of heat required to vaporize 32 g of boiling water to steam at 100oC is   72 J   720 J   7200 J   72000 J   Half-n-half Clue   4. The process by which a solid changes into its liquid state at a certain fixed temperature by the absorption of heat is called _______.   liquefaction   vaporization   solidification   fusion   Half-n-half Clue   5. The freezing point of salt water is less than 0oC.   True   False   6. The boiling point of salt water is less than 100oC.   True   False   7. When the cooling curve for naphthalene is plotted on a graph of temperature (in oC) vs. time (in minutes), the following three regions are observed: in the first 2 minutes, the temperature drops from 90oC to 80oC; in the next 6 minutes, the temperature remains constant at 80oC; and in the last 4 minutes, the temperature falls from 80oC to 60oC. The melting point of naphthalene is _______oC.   80   60   90   Half-n-half Clue