Question

a compound A is treated with compound B and A gas C is evolved which made lime water milky find out A, B, C what happens if C is passed through lime water for a longer period

Answer 1

Here A is HCl and B is NaHCO3,C is CO2 . When we pass CO2 for long time then milkiness of lime water disappears and the product formed is Ca(HCO3)2

Answer 2

Compound A is CH4 and compound B is O2 and compound C is CO2
CH4 + 2O2 - CO2 + 2H2O
and if compound C is passed through lime water for long time then limewater become colourless from milky white.