Test For Anions And Aqueous Cations

Question 1

Carbonate (CO3^2-)

Answer 1

Add dilute acid. Effervescence (bubbling), CO2 produced

Question 2

Chloride (Cl^-) in solution

Answer 2

1. Acidify with dilute nitric acid (HNO3)
2. Add aqueous silver nitrate (AgNO3)
   White Precipitate

Question 3

Nitrate (NO3^-) in solution

Answer 3

1. Add aqueous sodium hydroxide (NaOH)
2. Add aluminium foil
3. Warm carefully
   Ammonia Produced

Question 4

Sulfate (SO4^2-) in Solution

Answer 4

1. Add acid
2. Add aqueous barium nitrate (BA(NO3)2
   White Precipitate

Question 5

Ammonium (NH4^+]

Answer 5

Effect of Aqueous Sodium Hydroxide (NaOH) - Ammonia produced on warming
Effect of aqueous ammonia - no observation

Question 6

Calcium (Ca^2+)

Answer 6

Effect of aqueous sodium hydroxide (NaOH) - White Precipitate, insoluble in excess
Effect of aqueous ammonia - no precipitate or very slightly white Precipitate

Question 7

Copper (Cu^2+)

Answer 7

Effect of aqueous sodium hydroxide (NaOH) - light blue precipitate, insoluble in excess
Effect of aqueous ammonia - light blue precipitate, soluble in excess, giving dark blue solution

Question 8

Iron(II) (Fe^2+)

Answer 8

Effect of aqueous sodium hydroxide (NaOH) - green precipitate, insoluble in excess
Effect of aqueous ammonia- green precipitate, insoluble in excess

Question 9

Iron(III) (Fe^3+)

Answer 9

Effect of aqueous sodium hydroxide (NaOH) - red-brown precipitate, insoluble in excess
Effect of aqueous ammonia - red-brown precipitate, insoluble in excess

Question 10

Zinc (Zn^2+)

Answer 10

Effect of aqueous sodium hydroxide (NaOH) - white Precipitate, soluble in excess, giving a colourless solution
Effect of aqueous ammonia - white Precipitate, soluble in excess, giving a colourless solution