Chemistry- Identifying Cations and Anions

Question 1

state the 5 tests that can be done to identifying anions.

Answer 1

1. Heating
2. Dilute nitric acid or hydrochloric acid
3. Concentrated Sulphuric acid
4. Silver Nitrate then add ammonia solution
5. Barium Nitrate or Barium chloride

Question 2

State each anion that corresponds with the method used to identify them.

Answer 2

Heating- CO3^2-and NO3^-
Dilute nitric or hydrochloric acid- CO3^2-and SO3^2-
Concentrated Sulphuric acid- CO3^2-, SO3^2-, Cl-, Br- and I-
Silver Nitrate followed by aqueous ammonia- Cl-, Br- and a I-
Barium Nitrate or Barium Chloride- CO3^2-, SO4^2- and SO3^2-

Question 3

What is the observation made for heating the Carbonate anion? What is the equation?

Answer 3

Carbon dioxide is evolved which produces a white ppt in like water ( CO3^2- (s) > CO2(g) + O2(g)

Question 4

What is the observation made upon heating the Nitrate anion? What is the equation?

Answer 4

Nitrogen dioxide gas is evolved. A brown gas with a sharp pungent odour. Oxygen evolved relighting a glowing splint.

4NO3- > 4NO2(g) + O^2-(s)+O2(g)