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Which of the following is a proper buffer substituent pair?
a.
oxalic acid and lithium oxalate
c.
Neither a nor b
b.
carbonic acid and sodium carbonate
d.
Both a and b

Respuesta :

znk

Answer:

[tex]\boxed{\text{c. Neither a nor b is correct}}[/tex]

Explanation:

A buffer pair consists of either

  • A weak acid and its salt or
  • A weak base and its salt

(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]