Sulphates And Carbonates

SULPHATES

By action of $H_{2} S O_{4}$ on Metal, Metal Oxide, Metal Hydroxide and Metal Carbonate.

$M g + d i l . H_{2} S O_{4} \to M g S O_{4} + H_{2}$

$M g (O H)_{2} + H_{2} S O_{4} \to M g S O_{4} + H_{2} O$

$M g O + H_{2} S O_{4} \to M g S O_{4} + H_{2} O$

$M g O + d i l . H_{2} S O_{4} \to M g S O_{4} + H_{2} O$

$M g C O_{3} + d i l . H_{2} S O_{4} \to M g S O_{4} + C O_{2} + H_{2} O$

$(C H 3 COO)_{2} P b + H_{2} S O_{4} \to P b S O_{4} + 2 C H_{3} COO H$

-Most of the sulphates are soluble.

- $A g_{2} S O_{4}$ and $L i_{2} S O_{4}$ are sparingly soluble.

- $C a S O_{4}, C r S O_{4}, B a S O_{4}, P b S O_{4}$ are insoluble sulphates.

-Except alkali metal sulphates, all other metal sulphates are thermally unstable.

$2 M g S O_{4} \to 2 M g O + S O_{2} + O_{2}$

$2 F e S O_{4} \to F e_{2} O_{3} + S O_{2} + S O_{3}$

$2 P b S O_{4} \to 2 P b O + S O_{2} + O_{2}$

$2 N i S O_{4} \to 2 N i O + S O_{2} + O_{2}$

i) Passing $C O_{2}$ through Alkali:

$C O_{2} + 2 N a O H \to N a_{2} C O_{3} + H_{2} O$

$C O_{2} + C a (O H)_{2} \to C a C O_{3} + H_{2} O$

ii) By heating Bicarbonates:

$M g (H C O_{3})_{2} \to M g C O_{3} + C O_{2} + H_{2} O$

iii) By fusion with Sodium Carbonate:

$B a C l_{2} + N a_{2} C O_{3} \to B a C O_{3} ↓ + 2 N a Cl$

$M g S O_{4} + N a_{2} C O_{3} \to M g C O_{3} ↓ + N a_{2} S O_{4}$

iv) By Double Decomposition:

$P b (N O_{3}) + (N H_{4}) C O_{3} \to P b C O_{3} + 2 N H_{4} N O_{3}$

-Alkali metal carbonates are soluble in water except $L i_{2} C O_{3}$

-Alkali metal carbonates are thermally stable except $L i_{2} C O_{3}$ which is thermally unstable.

$L i_{2} C O_{3} \to L i_{2} O + C O_{2}$

-Other metal carbonates are thermally unstable.

$F e C O_{3} \to F e O + C O_{2}$

$P b C O_{3} \to P b O + C O_{2}$

$Z n C O_{3} \to Z n O + C O_{2}$