Zn (s) + CuSO (aq) = ZnSO (aq) + Cu (s)
In this investigation, I am going look at how the change in the mass of zinc affects the heat energy released during the reaction. Here are the equipment needed for the investigation:
- Polystyrene cup with a polystyrene lid
- Copper sulphate solution
- Zinc powder
- Thermometer
- Beaker
Here is the method: I will be taking a fixed volume of 50cm of copper sulphate and pour it in the polystyrene cup. I will measure the initial temperature of the copper sulphate after the temperature has become steady and note it down. Following this, I will add a certain amount of zinc into the solution and close the lid of the cup. During the reaction, I will constantly stir the solution and the maximum temperature reached will be recorded.
This experiment is being done using some 2 basic assumptions. The assumptions are that all the heat energy released during the experiment is transferred back to the solution because the polystyrene cup will not conduct heat; the copper sulphate solution will have a specific heat capacity and the density will be the same as water.
The heat energy released during the experiment will be calculated using the following formula: m x c x change in temperature , where m is the mass of the solution and c is the
specific heat capacity. The data collected will be recorded in a table like the one below.
To make it a fair test, all the variables besides the mass of the zinc will be kept constant. This is because if a second variable is altered, for example, the temperature, it will increase the rate at which the particles collide with each other thus affecting the results. To have a fair set of results, it is necessary to control the other variables.
I predict that as the mass of the zinc in the solution is increased, the heat energy released will increase with it.