Identical heat lamps are arranged to shine on identical containers of water and methanol (wood alcohol) so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?

Question

Quizplus · Accepted Answer

The graph shows that both water and methanol initially increase in temperature at the same rate, but once they reach their respective boiling points, the temperature of methanol remains constant while the temperature of water continues to increase. This is because water has hydrogen bonding which requires more energy to break than the nonpolar covalent bonds in methanol. Therefore, water requires more energy to reach its boiling point than methanol, and once it does, it continues to absorb energy and increase in temperature while methanol stays at its boiling point.

Identical Heat Lamps Are Arranged to Shine on Identical Containers