Among the compounds (i) $\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{COOH}$ (ii) $\mathrm{CH}_2=\mathrm{CH}-\mathrm{COOH}$ (iii) $\mathrm{CH}_3-\mathrm{CH}_2 \mathrm{COOH}$ and (iv) $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{OH}$ The correct order of acid strength is

• Correct answer
  A

  (i) > (ii) > (iii) > (iv)
• B

  (iv) > (iii) > (ii) > (i)
• C

  (ii) > (i) > (iv) > (iii)
• D

  (iii) > (ii) > (i) > (iv)

Solution

Carboxylic acids are more acidic than alcohol. As the 's'-character in the $\mathrm{C}_{\mathrm{x}}$ increases, the acidity of carboxylic acid increases.

Hence, the correct answer is option: 'A'.