MCQ
Which is the strongest acid ? ($pKa$ value is given in the bracket)
  • $HCOOH\,(3.77)$
  • B
    ${C_6}{H_5}COOH\,(4.22)$
  • C
    $C{H_3}COOH\,(4.71)$
  • D
    $C{H_3}C{H_2}COOH\,(4.88)$

Answer

Correct option: A.
$HCOOH\,(3.77)$
a
The $\mathrm{pK}_{\mathrm{a}}$ value indicates the strength of an acid. A lower $\mathrm{pK}_{\mathrm{a}}$ value indicates a stronger acid i.e, the lower value indicates the acid more fully dissociates in water.

: Formic acid with lower $\mathrm{pK}_{\mathrm{a}}$ value of 3.77 is the strongest acid.

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