Today in science we are doing a neutralisation experiment. We have been looking at what an universal indicator, base and acid is, and what is the pH scale. An universal indicator is a dye that shows the pH level and if it is a base or acid by changing colour. The pH scale goes from 1-14. A neutral is a 7 which is shown as green, acids range from 6-1 and are red. Bases range from 8-14 and are blue. Acids and bases are opposites of each other so when they combine the neutralise each other. Acids are sour and will corrode metal and other things. Bases are commonly used in cleaning products like oven cleaners.
Aim
To observe a neutral reaction
Equipment
Test tube, test tube rack, sodium carbonate, Hydrochloric acid, dropper, universal indicator solution
Method
- Add 2mL(2cm) of NaCH into a test tube
- 2 drops of universal indicator
- Add drops of HCl until you get a neutral green.
Observation
It was very easy to add to much HCl turning the solution red instead of green for neutral meaning we had to add even more NaCH to try and balance it out again. That also happened when we where trying to weaken the NaCH for a lighter blue for the rainbow.