lab tests (anions, cations, flames)

Question 1

Add dilute acid, test for CO2. Effervescence, CO2 produced.

Answer 1

Carbonate, CO3 (2-)

Question 2

Add dilute nitric acid + aq. silver nitrate. Cream ppt.

Answer 2

Bromide, Br (1-)

Question 3

Add dilute nitric acid + aq. silver nitrate. White ppt.

Answer 3

Chloride, Cl (1-)

Question 4

Add dilute nitric acid + aq. silver nitrate. Yellow ppt.

Answer 4

Iodide, I (1-)

Question 5

Add aq. NaOH + aluminium foil, then warm. Ammonia produced.

Answer 5

Nitrate, NO3 (1-)

Question 6

Add dilute nitric acid + aq. barium nitrate. White ppt.

Answer 6

Sulfate, SO4 (2-)

Question 7

Add a small volume of acidified aq. potassium manganate (VII). Turns purple to colourless.

Answer 7

Sulfite, SO3 (2-)

Question 8

Aluminium, Al (3+)
in NaOH

Answer 8

White ppt, soluble in excess, colourless solution

Question 9

Aluminium, Al (3+)
in Ammonia

Answer 9

White ppt, insoluble in excess

Question 10

Ammonium, NH4 (1+)
in NaOH

Answer 10

Ammonia produced on warming

Question 11

Ammonium, NH4 (1+)
in Ammonia

Answer 11

-

Question 12

Calcium, Ca (2+)
in NaOH

Answer 12

White ppt, soluble in excess

Question 13

Calcium, Ca (2+)
in Ammonia

Answer 13

No ppt / very little white ppt

Question 14

Chromium (III), Cr (3+)
in NaOH

Answer 14

Green ppt, soluble in excess

Question 15

Chromium (III), Cr (3+)
in Ammonia

Answer 15

Green ppt, insoluble in excess