Question 25
Carrying out an endothermic reaction
You will need: test tube; test tube rack; stirring rod; thermometer; spatula; lemon juice or citric acid; sodium hydrogencarbonate; safety glasses.
Method
1. Place some citric acid or lemon juice in a test tube so that it is about half full.
2. Measure and record the temperature.
3. Add three spatulas of sodium hydrogencarbonate and stir. Do not use the thermometer to do this.
4. Measure and record the temperature.
What was the difference between the temperature at the start and the end of the experiment?
You will need: test tube; test tube rack; stirring rod; thermometer; spatula; lemon juice or citric acid; sodium hydrogencarbonate; safety glasses.
Method
1. Place some citric acid or lemon juice in a test tube so that it is about half full.
2. Measure and record the temperature.
3. Add three spatulas of sodium hydrogencarbonate and stir. Do not use the thermometer to do this.
4. Measure and record the temperature.
What was the difference between the temperature at the start and the end of the experiment?
