Question

A is heated, a gas B is evolved which turns lime water milky. Compound A is used in manufacture of glass. Gas B has property of extinguishing fire. The compound A and B are

Answer 1

carbon co2 which is used as a fire extinguisher , carbon is bad conductor

Answer 2

Answer:

A is Sodium Carbonate(Na2CO3) which is also called soda ash and B is Carbon Dioxide(CO2)

Explanation:

B is clearly CO2 since it turns lime water milky(Due to formation of Calcuim carbonate) and is also used in fire extinguishers(Since Carbon dioxide extinguishers work because carbon dioxide molecules are heavier than oxygen molecules. When the liquid carbon dioxide inside the extinguisher expands into a gas, the carbon dioxide pushes out any oxygen surrounding the fire)  

A is soda ash since soda ash naturally reduces melting temperatures and its alkali effectively supports the shaping of the glass item, and is hence used in manufacture of glass.

Hope this helps.