SARAH DIX: Hello, and welcome to this core practical video. My name is Sarah Dix. I'm
a physics teacher here at Reddam House School. Today, we are going to be investigating the
properties of water so you can obtain accurate results in your own experiments.
The first experiment we'll be looking at is investigating the properties of water by determining
the specific heat capacity of water. To carry out this experiment, you will need the following--
a polystyrene cup, beaker, tripod, thermometer, stop clock, immersion heater, a Joulemeter,
and a balance.
Firstly, you need to place the cup onto the balance and press zero. This is to ensure
that you measure the mass of water only. Carefully add the water to the cup, and read the mass
from the balance. Place the cup into the beaker to support it, and then at the 12 volt electric
immersion heat to the water, making sure that your heating element is completely below the
water level. This is to ensure as much energy as possible is being transferred to the water
and not to the surroundings.
Now connect the immersion heater to the Joulemeter, but do not turn it on just yet. First, you
must record the temperature of the water. Now, turn on the immersion heater, and at
the same time, stop the stop clock.
Gently stir the water, and after five minutes, take the reading on the thermometer, making
sure that the thermometer is at the centre of the liquid and not touching the bottom
of the beaker, as we want to record temperature of the water, not the beaker. At the same
time, record the reading on the Joulemeter.
Before adding your data into the equation, you must convert the mass of the water from
grams into kilograms and work out the difference between your final temperature and starting
temperature. The change in thermal energy is simply the reading you have obtained from
your Joulemeter.
In the second part of this experiment, we'll be investigating how the temperature of ice
changes as it melts. To carry out this experiment, you will need the following-- a boiling tube,
beaker, tripod, gauze, Bunsen burner, stop clock hot water, and crushed ice.
To start this experiment, add some crushed into a boiling tube, and using a thermometer,
record the temperature of the ice. Now place the beaker carefully on top of the tripod
and gauze, and light the Bunsen burner, making sure you have it on a safety flame.
Carefully pour some hot water into the beaker. Place the Bunsen burner under the beaker and
warm using a moderate flame. During this time, you'll need to record the temperature of the
every minute until all the is melted and then for a further three minutes after the ice
has melted. Make a note of the time at which the starts to melt and when it appears to
be completely melted.
You now need to draw a line graph using the data you have collected. Using your physics
knowledge, you should now be able to explain the shape of the graph using your understanding
of what happens to the arrangement of particles when changing from a solid to a liquid.