an acid can react with
Sodium carbonate reacts with acid to form sodium chloride and water and release carbondioxide.
Sodium carbonate is basic in nature and thus reacts with acids. It is derived from NaOH, a strong base and weak acid, carbonic acid.
Na2CO3(s) + 2HCl(aq) --------> 2NaCl(aq) + H2O(l) + CO2 (g)
The above reaction is a double displacement reaction. (not neutralization as neutralization reaction occurs between an acid and a base).
AgCl does not react as Ag is less reactive than hydrogen and cannot displace hydrogen in the acid.
PbSO4 is an acidic salt while Na2SO4 is a neutral salt and both these do not react with acids.
The answer is b. Na2CO3
A dilute acid reacts with Na2CO3 as it is a basic salt. Its parent acid is carbonic acid and parent base is sodium hydroxide. The reaction is a neutralization reaction.
AgCl cannot react with acid because silver is less reactive than hydrogen and is not able to displace it from dilute acids.
PbSO4 is an acidic salt. Its parent acid is sulphuric acid and parent base is lead hydroxide (a weak base). Hence it does not react with any dilute acid.
Na2SO4 is a neutral salt. Its parent acid is sulphuric acid and parent base is sodium hydroxide. Being neutral it does not react with any dilute acid.