alkali metals

Ans is option (A)NaHCO₃ and NaOH

ya ans is NaHCO₃ and NaOH,as the former is an acid salt and the latter is a base.

it is not an acid salt it is a basic salt
reason :it is formed from strong base NaOH and weak mineral acid H₂CO₃

No one can claim that NaHCO3 is an acid salt because of the H in the formula. In order to be

an acid salt it must produce or cause the production of an ionisable H+ . NaHCO3 does not

do this. The reaction equation of NaHCO3 in water is:

NaHCO3 + H2O → Na+ OH- + H2CO3.

The H2CO3 is unstable and breaks down to CO2 and H2O

The basicity of the solution comes from the OH- ions produced.

khyati is right ...NaHCO₃ is amphoteric salt
it is formed as a result of partial nuetralisation of salt Na₂CO₃
Na₂CO₃ + HCl → NaHCO₃ + NaCl
it can act as both acid and base in a solution and whether it will act as acid or base depends on the other reactant (with which it is being reacted)
if the other reactant is significantly basic(like NaOH in the above question) it will act as an acid
if the other reactant is acidic(like HCl/H₂SO₄) then it will act as a base
I have seen this question in many books ..in most of them the reason given is that NaHCO₃ is a acid salt but it is given in accordence with the question because in the reaction given in the question it is acting as an acid salt..but actually it is amphoteric salt

Thanks Vaibhav for the awesome answer :)