Question

In a chemical reaction, element A which is an important constituent in bones reacts with a colourless gas B, that is a supporter of combustion to form a compound AB. Identify the element A and the general name of the compound AB
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Answer 1

Answer:

thanks for free points

Answer 2

Answer:

The reactions can be summarized as follows :

A

→

Δ

colorless gas + residue

residue + H

2

O → B

→

ExcessCO

2

C

→

Δ

A

This is possible only when A is CaCO

3

. The reactions are as follows

CaCO

3

→

Δ

(colourlessgas)

CO

2

+

(residue)

CaO

CaO+ H

2

O →

(B)

Ca(OH)

2

CO

2

(excess)

(C)

Ca(HCO

3

)

2

→

Δ

CaCO

3

Thus, calcium carbonate on heating gives colourless gas carbon dioxide and residue calcium oxide. Calcium oxide reacts with water to form calcium hydroxide. Calcium hydroxide reacts with excess carbon dioxide to form calcium hydrogen carbonate. This on heating gives calcium carbonate.