Answer:
[tex]\boxed{\text{c. Neither a nor b is correct}}[/tex]
Explanation:
A buffer pair consists of either
(a) Oxalic acid and sodium oxalate
[tex]\rm H$_2$C$_2$O$_4$ + Li$_2$C$_2$O$_4$ \longrightarrow \, $2LiHC$_2$O$_4$[/tex]
Oxalic acid is an acid and lithium acid is a base. Together, they will neutralise each other and form the salt LiHC₂O₄.
A solution of LiHC₂O₄ is not a buffer.
The correct buffer pair is H₂C₂O₄ and LiHC₂O₄
(b) Carbonic acid and sodium carbonate
[tex]\rm H$_2$CO$_3$ + Na$_2$CO$_3$ $\longrightarrow \,$ 2NaHCO$_3$[/tex]
The carbonic acid and the sodium carbonate will neutralise each other and form the salt NaHCO₃.
A solution of NaHCO₃ is not a buffer.
The correct buffer pair is H₂CO₃ and NaHCO₃
[tex]\boxed{\textbf{Neither a nor b is correct}}[/tex]