Identifying Ions

Question 1

Carbonate

Answer 1

CO3-

Add HCl and pass the released gas through limewater to form a cloudy white precipitate

Question 2

Chloride

Answer 2

Cl-

If you add silver nitrate solution, forms white precipitate

If you add nitric acid, forms insoluble precipitate but then after adding NH4OH, the precipitate dissolves

Question 3

Hydroxide

Answer 3

OH-

This ion turns red litmus paper blue

Question 4

Sulfate Ion

Answer 4

(SO4)2-

Forms a white precipitate with BaCl2 and this precipitate is insoluble in HCl

Question 5

Sulfide

Answer 5

S2-

Add HCl and test the gas released with lead acetate paper. The rotten-egg-smelling gas turns the paper brown-black.

Question 6

Ammonium

Answer 6

NH4+

After adding strong base and gently heating, smells like ammonia.

Question 7

Ferrous or Iron (II)

Answer 7

If you add potassium ferrocyanide (K3Fe(CN)6), a dark blue (Turnball’s blue) precipitate forms

Question 8

Ferric (Iron (III))

Answer 8

Fe3+

Forms a Prussian blue (dark blue) precipitate with potassium ferrocyanide

Question 9

Hydrogen

Answer 9

H+

Turns blue litmus paper red

Question 10

Acetate

Answer 10

C2H3O2-

If you add concentrated H2SO4 and heat gently, smells like vinegar