what is the role of NH3(ammonia) in the precipitation?

Answer 1

It would help if u specified what precipitation reaction u are dealing with. However, dilute ammonia solution can be used to determine some of the cations (i.e. positive ions) present in a substance through a process called qualitative analysis.

For example: Adding dilute ammonia dropwise to a solution which contains Cu2+ ions will produces a blue precipitate. If the ammonia is then added in excess the precipitate will dissolve leaving a deep blue solution. This is an example of qualitative analysis

Answer 2

It is a weak base as it takes up a protron and forms the ammonium ion NH4+, decreasing the concentration of H3O+ ions. So it will increase the pH level.

So if you have a chemical reaction that is acid on the left and basic on the right, NH3 will drive the reaction to the right side. If the basic side is less soluble a precipitation will form.

So to fully answer this question you would need to know the entire reaction and the solubility of the products and the reactants.

Answer 3

I would like to say that NH3 and NO3 compounds are the most soluble in water, so it hard to find any compound of these anions insoluble,, so the role of NH3 in chemical reactions is to change the pH from acid to basic to allow some oxides as iron or M2O3 to precipitate

Answer 4

its is a cation that reacts with the other substance's anion, such as sulphate, forming a precipitate of ammonium sulphate... which can be further identified through a series of tests and observations.

Answer 5

it helps in two ways

1.by changing the pH to basic
2.by reacting chemically with the materials.

Answer 6

It is polar and hence plays a role in changing the pH level.