1. 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 naphthalene is a mixture of liquid and solid in the time interval from _______.   0 to 2 minutes   2 to 8 minutes   8 to 12 minutes   Hint Half-n-half Clue   2. Water vapor is invisible.   True   False   3. 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   4. Hail is formed due to a change of state from vapour to solid.   True   False   5. The heat gained or lost by a body during a change of state is referred to as _______ heat since there is no change in temperature.   latent   specific   sensible   Half-n-half Clue   6. The process by which a _______ changes into its gaseous state at a certain fixed temperature by the absorption of heat is called vaporization.   liquid   solid   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 naphthalene is a liquid in the time interval from _______.   0 to 2 minutes   8 to 12 minutes   2 to 8 minutes   Half-n-half Clue