Acids And Bases Tests

Question 1

Al 3+

Answer 1

NaOH: white, soluble precipitate. Colourless solution.
Ammonia: white precipitate formed.

Question 2

NH4 +

Answer 2

NaOH: ammonium gas produced, turns damp red litmus blue.

Question 3

Ca 2+

Answer 3

NaOH: white precipitate
Ammonia: no precipitate

Question 4

Cu 2+

Answer 4

NaOH: light blue precipitate
Ammonia: dark blue solution

Question 5

Fe 2+

Answer 5

NaOH: green precipitate
Ammonia: green precipitate

Question 6

Fe 3+

Answer 6

NaOH: red-brown precipitate
Ammonia: red-brown precipitate

Question 7

Zn 2+

Answer 7

NaOH: white soluble precipitate, colourless solution
Ammonia: white soluble precipitate, colourless solution

Question 8

CO3 2-

Answer 8

Add dilute nitric acid

Limewater turns cloudy

Question 9

Cl-, Br-, I-

Answer 9

Add dilute nitric acid + aqueous silver nitrate

Cl: white, Br: cream, I: yellow

Question 10

NO3 -

Answer 10

Aqueous sodium hydroxide + aluminium

Gas turns red litmus blue

Question 11

SO4 2-

Answer 11

Dilute nitric acid + aqueous barium nitrate

White precipitate formed

Question 12

Gases

Answer 12

Ammonia: damp red litmus turns blue
CO2: limewater turn cloudy
Cl-: bleaches litmus paper
H+: lighted splint, squeaky pop
O2: glowing splint relights.