How do Acids and Bases React with each other?
- Take about 2 mL of dilute NaOH solution in a test tube and add two drops of phenolphthalein solution.
- What is the colour of the solution?
- Add dilute HCl solution to the above solution drop by drop.
- Is there any colour change for the reaction mixture?
- Why did the colour of phenolphthalein change after the addition of an acid?
- Now add a few drops of NaOH to the above mixture.
- Does the pink colour of phenolphthalein reappear?
- Why do you think this has happened?
In the above Activity, we have observed that the effect of a base is nullified by an acid and vice-versa. The reaction taking place is written as –
NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
The reaction between an acid and a base to give a salt and water is known as a neutralisation reaction. In general, a neutralisation reaction can be written as –
Base + Acid → Salt + Water