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Bergen Community College
Physics II Lab

Heats of Fusion and Vaporization of Water
PHY 290-002
Written By: Sait Bilal Cantas
Team Members: Bruce Le, Mikhaiel Myshkin
Date of Experiment:
Report submitted on:

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OBJECTIVES:
The main objective of the experiment is to examine the latent heat of water i.e. latent heat of
fusion and latent heat of vaporization.
PHYSICAL PRINCIPLES:
The change in state of a substance from one state to the other (solid to liquid or liquid to gas)
heat energy is responsible for change in the intermolecular forces. The heat is referred to as
latent heat. The mass of water is directly proportional to temperature change and change in heat
energy and is given by
Equation 1

∆𝑄 = 𝑚𝑐∆𝑇
The graph of temperature vs. heat energy for a given mass of water is as shown

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𝑐𝑤𝑎𝑡𝑒𝑟 = 1.0 𝑘𝑐𝑎𝑙/𝑘𝑔 − 𝑖𝐶
𝑐𝑖𝑐𝑒 ≈ 𝑐𝑠𝑡𝑒𝑚 = 0.5 𝑘𝑐𝑎𝑙/𝑘𝑔 − 𝑖𝐶
Essentially,
𝑐𝑖𝑐𝑒 = 0.5𝑘𝑐𝑎𝑙/𝑘𝑔 − 𝑖𝐶
𝑐𝑖𝑐𝑒 = 0.48𝑘𝑐𝑎𝑙/𝑘𝑔 − 𝑖𝐶
During the phase of freezing and boiling points, any addition of heat will not affect the
temperature as shown in the above graph. The heat energy is used to increase intermolecular
movement that is reflected as temperature rise.
The latent heat is the amount of energy needed to change the state of a unit mass of a substance
(without increase or decrease in temperature).
Equation 2

∆𝑄 = 𝑚𝐿𝑖
Where
𝑚 = 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑠𝑢𝑏𝑠𝑡𝑎𝑛𝑐𝑒
𝐿𝑖 = 𝑙𝑎𝑡𝑒𝑛𝑡 ℎ𝑒𝑎𝑡 𝑓𝑜𝑟 𝑝𝑎𝑟𝑡𝑖𝑐𝑢𝑙𝑎𝑟 𝑝ℎ𝑎𝑠𝑒 𝑜𝑓 𝑐ℎ𝑎𝑛𝑔𝑒
Heat of fusion
This is the amount of heat required to convert substance in ice state (0℃) to liquid state without
change in temperature. In the experiment using calorimeter, the heat of fusion required to melt

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the ice plus the heat gained by the ice water equals heat lost by warm water plus heat lost by
calorimeter cup and stirrer
∆𝑄𝑓𝑢𝑠𝑖𝑜𝑛 + ∆𝑄𝑖𝑐𝑒 𝑤𝑎𝑡𝑒𝑟 = ∆𝑄𝑤𝑎𝑟𝑚 𝑤𝑎𝑡𝑒𝑟 + ∆𝑄𝑐𝑎𝑙𝑜𝑟𝑖𝑚𝑒𝑡𝑒𝑟 𝑐𝑢𝑝 𝑎𝑛𝑑 𝑠𝑡𝑖𝑟𝑟𝑒𝑟

Equation 3

𝑚𝑖 𝐿𝑓 + 𝑚𝑖 𝑐𝑤 (𝑇𝑓 − 0) = (𝑚𝑤 𝑐𝑤 + 𝑚𝑐𝑠 𝑐𝑐𝑠 (𝑇ℎ − 𝑇𝑓 )
Heat of vaporization
This is the amount of heat required to convert substance in liquid state to vapor state without
change in temperature. In the experiment using calorimeter, the heat of vaporization required to
vaporize the liquid plus the heat lost by the condensed water equals heat gained by cool water
plus heat gained by calorimeter cup and stirrer
∆𝑄𝑣𝑎𝑝𝑜𝑟𝑖𝑧𝑎𝑡𝑖𝑜𝑛 + ∆𝑄ℎ𝑜𝑡 𝑤𝑎𝑡𝑒𝑟 = ∆𝑄𝑐𝑜𝑜𝑙 𝑤𝑎𝑡𝑒𝑟 + ∆𝑄𝑐𝑎𝑙𝑜𝑟𝑖𝑚𝑒𝑡𝑒𝑟 𝑐𝑢𝑝 𝑎𝑛𝑑 𝑠𝑡𝑖𝑟𝑟𝑒𝑟
𝑚𝑠 𝐿𝑣 + 𝑚𝑠 𝑐𝑤 (100 − 𝑇𝑓 ) = (𝑚𝑤 𝑐𝑤 + 𝑚𝑐𝑠 𝑐𝑐𝑠 (𝑇𝑓 − 𝑇𝑐 )
LIST OF EXPERIMENTAL EQUIPMENT:
Calorimeter

Steam generator and stand

Laboratory balance

Hot plate or Bunsen

Rubber hose

Ice

Water trap

Beaker

burner and striker
2 thermometers (0°C
to 110°C)
Safety glass

Paper towels

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Figure 2:Calorimeter

Figure 2:
Thermometer

EXPERIMENTAL PROCEDURE
A. Heat of Fusion
i.

Some water was heated in a beaker to about 15 °C above room temperature. Meanwhile,
the mass of the inner calorimeter cup with stirrer (mcs) was determined and recorded
alongside the type of metal and its specific heat.

ii.

The inner calorimeter cup was filled with warm water to about half full and weighed with
the stirrer (mw). The calorimeter cup was placed in its jacket and the lid placed on with
the thermometer reaching the water. The water was stirred gently while recording its
temperature Th.

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iii.

Pieces of ice were dried with a towel and added one at a time into the calorimeter cup
with splashing.

iv.

The water-ice mixture was added more pieces of ice while being stirred gently until the
temperature was about 15 °C below the room temperature. The final temperature was
recorded after it had stabilized (Tf). The inner calorimeter cup was weighed with its
contents in order to determine the mass of ice mi.

v.

The heat of fusion Lf was computed using equation 3 and compared with the accepted
value using a percentage error.
B. Heat Vaporization

vi.

Steam generator was set up as shown below.

vii.

The inner calorimeter cup was filled with cool water to about two-thirds full, weighed
with the stirrer before placing in the jacket and closed it. The temperature was recorded
as Tc.

viii.

Steam from the steam generator was introduced into the calorimeter wat...