What is the reaction when universal indicator is added to sodium chloride

Hello there !

It can be difficult to add exactly the right amount of acid and alkali in a neutralisation reaction so that your salt solution is precisely pH 7. You can check the reaction mixture using universal indicator or a pH meter to see when it becomes pH 7, but a little acid or alkali is often left over.

Hope this helped!

The gas would begin to expand, and eventually the can would burst or explode.