Neutralising Reactions

Throughout our newest Science topic, Acids and Bases, we have been learning about things such as pH testing and making our own indicators out of household chemicals, foods and other items. The latest experiment was Neutralisation, where we combined some acid and some base as well as Universal indicator to attempt to create a neutral solution.

Aim: To observe or create a neutralisation reaction.

Equipment:

A test tube
Test tube rack
1 mol L(-1) Na(2)CO(3) (sodium carbonate),
1 mol L(-1) HCl (hydrochloric acid)
Dropper or dropper bottle / Pippette
Universal indicator solution

Method:

1. Add approximately 1-2mL of the Na(2)CO(3) and place the test tube into the test tube rack.
2. Add 3-5 drops of Universal indicator.
3. Using a dropper bottle or dropper, add the HCl drop by drop. Be careful, even two drops extra can make you miss the neutralisation point.

Results:

During this experiment, while we did reach a neutralisation point, we were able to create a rainbow out of the colours we made. Using decisive and exact amounts of acid and base to create a precise colour to add to the six colours of the rainbow we made, this included red, orange, yellow, green, blue and violet.

Discussion:

During the experiment we attempted to balance the colours in the pH levels, the strongly acidic solutions are identified by the universal indicator as red, on the pH scale the strongest acidic solutions that appear red have a pH level of 1 - 2. On the other end of the spectrum, the deep violet colour shown to us by the universal indicator is an extremely basic solution, with the pH scale knowing it as a solution most likely between the levels of 13 - 14. While the opposite spectrum ends are quite interesting, the real experiment was the green solution. When experimenting with the acids and bases, after mixing them together, with the universal indicator as well, it is somewhat difficult to create the solution, due to how quickly it can switch from a yellow solution to a blue one with too much base.

Conclusion:

In the end, our experiment was successful as multiple of the people within our group were able to create a neutral solution. Multiple of us due to a small race we had to attempt to create a neutral solution first.