Ammonia is a gas with the chemical formula NH3, and it is typically available as a liquid solution. Interaction of ammonia with water is accompanied by the release of hydroxyl anions. Therefore, the ammonia solution is basic. On the pH scale, basic solutions have a pH above 7, while a pH of 7 corresponds to the neutral media. You can neutralise the ammonia solution by adding a hydrochloric acid solution.
Pour the ammonia solution into the beaker.
Using the plastic pipette, add one to two drops of the hydrochloric acid solution to the beaker. Swirl the beaker for two to three seconds to mix the solution.
Detach a strip of the hydrion pH paper.
Holding one end of the pH paper strip, put the other end into the solution in the beaker for one to two seconds, and then take it out. The part of the paper that was in the solution should change colour.
Compare the colour of the paper with the scale printed on the pH paper pack. Assign pH accordingly.
Repeat this process until the pH of the solution in the beaker becomes "7" or neutral.
Things you need
- Hydrochloric acid solution (3 molar concentration)
- Plastic pipette
- Hydrion pH paper