Aqueous Solution

Question 0

test for bromides and iodides

Answer 0

Given: A solution of an unknown salt
Add: Silver nitrate
If the result is a pale yellow precipitate then the salt is either a bromide or a iodide.
Add: chlorine water and carbon tetrachloride.
If the chlorine water forms a bromide gas and carbon tetrachloride turns a reddish brown, the anion is a bromide.
If the chlorine water forms a iodine gas and the carbon tetrachloride turns puple, then the anion is a iodide.

Question 1

Test for chloride

Answer 1

Given: A solution of an unknown salt
Add: Silver nitrate
If the result is a white precipitate then the salt is either a chloride or a carbonate.
Then add concentrated nitric acid.
if precipitate is unchanged, then the salt is a chloride. If carbon dioxide is formed, it is a carbonate.

Question 2

Test for sulphate

Answer 2

Given: A solution of an unknown salt
Add: Barium chloride
If the result is a white precipitate then the salt is either a sulphate or a carbonate
Add: Nitric acid
If the precipitate disappears then it is a carbonate.
If the precipitate remains unchanged, then it is a sulphate.

Question 3

Test for carbonate

Answer 3

Add acid to the dry salt.
if carbon dioxide is produced, then it is a positive test for carbonate.
If the gas is passed through limewater, and it becomes milky, then the gas is carbon dioxide.