# Lab: Specific heat capacity.

Essay by eviiil October 2005

Aim:

i) To find the relationship between supplied energy and change in temperature of water.

ii) To find the specific heat capacity (SHC) of water.

Hypothesis:

As time increases so does the temperature since the water is exposed to the heated

wire for a longer period of time.

Variables:

The Dependent Variable is the temperature of the water, and since the Energy is calculated using temperature it is a dependent variable as well. The constant variables are the voltage and current.

Theory:

Energy Supplied by Heater = Energy Received by Water

Materials:

200ml beaker Connecting Wires Thermometer

200ml water Voltmeter Electronic scale

NiCr-Wire Ampmeter DC Power Supply

Crocodile Clips Stopwatch

Instructions:

i) Assemble the apparatus as shown in the diagram. You need to build your immersion heater by winding the NiCr-wire around a pencil say 8 to 10 times.

ii) Take first measurements of the water incl. its mass and its initial temperature.

iii) Place the immersion heater into the water and turn on the power supply. Adjust the voltage across the immersion heater around 12 to 15 volts.

iv) Measure and record time, voltage, current and temperature at regular intervals in a suitable table (include uncertainties)

v) Draw a suitable graph that will allow you to find the specific heat capacity of the water.

vi) Compare your findings with accepted values for water.

Observations:

One can observe the process of diffusion and the water changes its color, from clear to a yellowish solution. On one of the poles Nickel starts to accumulate (Electrolysis).

Results:

Mass of Beaker = 205,23 g (0.205 kg)

Mass of Beaker + Water = 391,41 g (0.391 kg)

Mass of Water = 186,18 g (0.186 kg)

Specific Heat Capacity of Water (15ÃÂC) = 4186 J/kgCÃÂ

V (v)

I (amps) t (s) T (ÃÂC) Ã¢ÂÂT (ÃÂC)...