Hypothesis
Increasing the amount of alkali solution causes the amount of acid solution required for neutralisation to increase.
Equipment
- Sodium Hydroxide solution
- Phenolphthalein solution
- Dilute hydrochloric acid
- White tile
- Conical flask
- Small measuring cylinder
- Burette and funnel
Method
First of all measure a small amount (10 centimetres cubed) of sodium hydroxide solution into the conical flask. Add 3 drops of phenolphthalein and place the conical flask onto the white tile. Using the burette, slowly add hydrochloric acid solution to the until the sodium hydroxide is neutralised. Record how much hydrochloric acid was needed to neutralise the sodium hydroxide. Repeat the process increasing the amount of sodium hydroxide solution each time.
Risk Assessment
Take care handling the chemicals - wear goggles and handle any spill appropriately. Perform the experiment standing up, keeping the area around the experiment clear of bags,coats etc. This is a low risk experiment.