DETERMINATION OF LATENT HEAT OF ICE

EXPERIMENT IIB

TITLE : DETERMINATION OF LATENT HEAT OF ICE

APPARATUS :

 Ice, calorimeter, triple beam balance , digital scale , water , stirrer.

DIAGRAM:

AIM: 

To determine the latent heat of fusion of ice.

THEORY:

 When a solid has reached it is melting point, additional heating melts the solid without  temperature change. The temperature will remain constant at tej melting point until all the solid has melted. The amount of heat needed to melt the solid depends only on the mass of the solid.

Q = MLf -------(1)

Where Q – amount of heat absorbed by the solid,

M – mass of the solid. 

If – latent heat of fusion measured in calls.

Ice will be avoided to a calorimeter containing warm water. The heat energy lost by the water and calorimeter does two things. It melts the ice and (2) it warms the water formed by melting kxe from zero to the final temperature.

TABLES OF VALUES

PROCEDURE:

1 . A calorimeter and stirrer which is empty is weighed.

2 . Fill the calorimeter to about half – full with warm water of about 20°C above room temperature.

3 . The calorimeter is weighed and the mass of the calorimeter and water (mcw) is gotten and recorded.

4 . Measure and record the initial temperature of the water, Tw. 

5 . Dry several small pieces of ice with a paper towel to remove any adhering water to ensure that liquid is not added.

6 . Add the pieces of ice to the calorimeter and keep adding to ice periodically until the temperature of the mixture is between 5°C and 10°C below room temperature. Keep the mixture well stirred.

7 . When all the ice has melted, measure and record the equilibrium temperature (Tf)

8 . Measure and record the combined mass of the calorimeter cup and water, which now includes water from the melted ice Mcw

9 . Calculate and record the mass of the ice, Mice = Mcwi – Mcw.

EXPERIMENT 1

TABLE OF VALUES

PRECAUTION OF DETERMINATION OF LATENT HEAT OF ICE

1 . It was ensured that the calorimeter used was lagged properly in order to prevent heat loss to the surrounding.

2 . The experiment was conducted at room temperature in order to get accurate results.

3 . The measuring instruments were in good condition before use, 

RESULT:

The latent heat of fusion of naphthalene (melting point) is 74°C from the graph.

CONCLUSION: 

A solidifying liquid absorbs latent heat during solidification and the temperature (melting point) remains constant.

GRAPH

Note ; if you are determination of melting point of a solid(including this, just make use of only this graph)