Question

5. Magnesium oxalate when heated at temperature above 400°C shows a loss in weight
due to evolution of
(a) O2
(b) H2O (c) CO2 (d) CO +CO2​

Answer 1

Answer:

C0+C02

Explanation:

here at 150°C it decompose to CO which then form C02

so at 400°C both C0 and C02 will be evolved

Answer 2

OPTION (b) IS CORRECT.

(b) H2O

Explanation:

• The magnesium oxalate contains 2 molecule of water.
• Its formula is $MgC_{2} OC_{4} .2H_{2} O$.
• It is prepared from the reaction of magnesium metal with oxalate ions.
• When it is heated, it will loose the water molecules. So it change from  $MgC_{2} OC_{4} .2H_{2} O$ to $MgC_{2} OC_{4}$.
• This will lead to the decrease in the weight of magnesium oxalate.

        $MgC_{2} OC_{4} .2H_{2} O--- > MgC_{2} OC_{4} +2H_{2} O$

• The anhydrous magnesium oxalate further decomposes to carbon mono-oxide and magnesium carbonate.
• Therefore, option (b) is correct.