8C 4 OTHER REACTIONS OF HALIDES

Testing for halides using silver nitrate, what do these test depend on?

1. The test depend on the very low solubility of silver halides in water and their different solubility in aqueous ammonia.

What is added before the silver nitrate solution to test for halides?

1. Dilute nitric acid is added, to make sure other anions are removed, as they would also form precipitates.

List what needs to happen in this test?

1. Add nitric acid to remove other anions(specially carbonate)

2. Add silver nitrate

3. Observe results, add ammonia solution(concentrated or dilute) and observe again.

Describe what will be observed in this test for chloride ions?

1. After adding silver nitrate, a white precipitate of silver chloride formed.

2. After adding dilute aqueous ammonia, the milky solution turns clear,

3. If concentrated aqueous ammonia is added the same result will be observed as dilute aqueous ammonia.

describe what will be seen when the test is used to test for bromide ions.

1. After adding silver nitrate solution, the mixture shows a cream precipitate of silver bromide.

2. Adding dilute aqueous ammonia after the silver nitrate would result in no change.

3. Adding concentrated aqueous ammonia instead would result in a clear solution as the products are soluble.

Describe the silver nitrate test with iodide ions.

1. After adding sliver nitrate, a yellow precipitate can be seen.

2. The mixture formed is insoluble in both concentrated and dilute aqueous ammonia . So no change.

Why must ammonia solution be added after silver nitrate?

1. The precipitates of all three test look too similar,

2. aqueous ammonia is a good solvent as the ability of the different mixtures to dissolve in it are different.

Describe the solubility of the three different silver halides in aqueous ammonia?

1. AgCl can be dissolved in both dilute and concentrated aqueous ammonia.

2. AgBr can only be dissolved in concentrated aqueous ammonia, it cannot be dissolved in dilute aqueous ammonia.

3. AgI cannot be dissolved in both concentrated and dilute aqueous ammonia.

Write the equation for the formation of the o plex ion that allows dissolving of the preipitate?

Write down the names of the acids formed and the equations of the hydrogen halides in water.

All of hydrogen halides are colorless gases and exist as polar diatomic molecules, true or false?

1. True

What is formed when hydrogen halides react with ammonia?

1. They all form salts which are white ionic solids.

There is an experiment where concentrated ammonia and concentrated HCl are soaked into cotton. The two cotton pieces are placed at opposite ends of the tube. The tube is sealed. After sometime, misty smoke appears near the HCl side why and what is it?

1. The white solid is ammonium chloride.

2. It appears closer to the HCl side, because ammonia gas is lighter, Mr smaller.