Apparatus
- Calorimeter with a stirrer
- Water
- Thermometer
- Flask with a delivery tube
- Heat source
- Weighing machine
Procedure
1. Set up the apparatus as shown above.
2. Find the mass of the calorimeter when empty and when filled with water to the level shown.
3. Measure and record the initial temperature of water in the calorimeter.
4. Heat the water in the flask until it delivers steam through the delivery tube. Ensure that the free end of the delivery tube is inside water in the calorimeter.
5. Allow steam to bubble into the water while stirring until the temperature of water rises by about 200C above the room temperature.
6. Remove the delivery tube from the calorimeter and record the temperature of the water.
7. Determine the new mass of the calorimeter and its contents. Hence, determine the mass of the condensed steam.
Note
Steam first condenses to water which then cools down, losing heat energy.
Therefore, heat energy lost by steam and the cooling water equal to the heat energy gained by the water and calorimeter.
mlv + mc??h = mc??w+ mc??c
Lv= (mc??w+ mc??c- mc??h)/m
It is important to first cool the water in the calorimeter to a certain value below the room temperature and then pass the steam through it until the temperature rises above the room temperature by the same value. This will help minimize errors due to the heat loss to the surrounding.
sharon kalunda answered the question on
April 24, 2019 at 09:55