Cations (precipitations)

Question 1

Aluminium

Answer 1

With NaOH :
White precipitate and soluble in excess forms a colorless solution
With NH3 :
White precipitate and insoluble in excess

Question 2

Ammonium

Answer 2

With NaOH :
Ammonia (NH3) is formed when warmed
With NH3
No reaction

Question 3

Calcium

Answer 3

With NaOH :
White precipitate and insoluble in excess
With NH3
No precipitate

Question 4

Copper (II)

Answer 4

With NaOH :
Blue precipitate and insoluble in excess
With NH3 :
Blue precipitate and soluble in excess forming a dark blue solution

Question 5

Chromium (III)

Answer 5

With NaOH :
Green precipitate and soluble in excess
With NH3 :
Grey-green precipitate and insoluble in excess

Question 6

Iron (III)

Answer 6

With NaOH :
Rust brown precipitate and insoluble in excess
With NH3 :
Rust brown precipitate and insoluble in excess

Question 7

Iron (II)

Answer 7

With NaOH :
Green precipitate and insoluble in excess
With NH3 :
Green precipitate and insoluble in excess

Question 8

Zinc

Answer 8

With NaOH :
White precipitate and soluble in excess
With NH3 :
White precipitate and soluble in excess