Page 23 - Ranger PT3 2022 science

Science PT3 Chapter 5 Water and Solution

(A) Surrounding temperature Wet cobalt paper
The higher the surrounding temperature, Table lamp
the higher the rate of evaporation of
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water.
Results:
Cobalt chloride paper B dries first. Tile
Discussion: A B
The temperature below the lamp is high.
A high temperature gives energy to the water molecules to move faster and
then escape into the air. Therefore, the rate of evaporation of the water
increases as the temperature increases.

(B) Exposed surface area of water
The larger the exposed surface area
of water, the higher the rate of C D E
evaporation of water.
Results:
Filter paper C dries first followed by Wet filter paper
filter D and E. Retort stand
Discussion:
Filter paper C has a larger surface area, which allows more water molecules to
escape into the air.

(C) Movement of air
The higher the movement of air, the higher
the rate of evaporation of water. Fan
Results: Form 2
Cobalt chloride paper G dries first. Wet cobalt chloride paper
Form 2
Discussion:
The movement of air under the fan is higher.
High speed air movement sweeps away the F G
water vapour from the surface of the water to other places causing the air at
the surface of the water to dry and increases the rate of evaporation.
(D) Humidity
The higher the humidity, the lower the rate of Wet cobalt chloride paper
evaporation of water.
Results: Bell jar
Cobalt chloride paper I dries first.
Discussion: Anhydrous
calcium
The presence of anhydrous calcium chloride H chloride I
absorbs water vapour and causes the air inside
bell jar I to dry. Dry air can hold more water molecules that escaped from the
surface of the water.

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