Heat is added to a 200.-gram sample of H2O(s)
to melt the sample at 0°C. Then the resulting H2O(*ℓ*)
is heated to a final temperature of 65°C.

59 Determine the total amount of heat
required to completely melt the sample. [1]

**HIGHLIGHT TO SEE THE ANSWER**

ANSWER=
66 800 J or 6.68
×
10^{4
}
J
NOTE=the
question was only asking for the energy to melt
Q=mHf
Q=200g(334J/g) |

60 In the space
*in your answer
booklet*, show a numerical setup for calculating
the total amount of heat required to raise the temperature
of the H2O(*ℓ*)
from 0°C to its final temperature. [1]

**HIGHLIGHT TO SEE THE ANSWER**

Just the
setup (DON'T ANSWER IT)
Q=mCDT *
q *
=
(200. g)(4.18
J/g•°C)(65°C)
(200)(4.18)(65) |

61 Compare the amount of heat required to
vaporize a 200.-gram sample of H2O(*ℓ*)
at its boiling point to the amount of heat required to melt
a 200.-gram sample of H2O(s)
at its melting point. [1]

**HIGHLIGHT TO SEE THE ANSWER**

NOTE=Hv
(2260J/g) vs. Hf (334J/g)
The heat
necessary to vaporize 200 grams of water is
about seven times larger than the heat necessary
to melt 200 grams of ice.
It takes more heat to
vaporize the same amount of H2O(*ℓ*). |