\(2HC = CH_2\text{Cl}_2 \xrightarrow{\text{A}} \text{NH}_4\text{Cl}\) \(\xrightarrow{\text{B}}\) \(\text{Identify the compounds A and B}\)






Arrange the following compounds in order of their increasing acid strength. 

Compound given below will produce effervescence when mixed with aqueous sodium bicarbonate solution 