The standard enthalpies of formation of $A\left(\mathrm{NH}_3\right), B\left(\mathrm{CO}_2\right), C(\mathrm{HI})$ and $D\left(\mathrm{SO}_2\right)$ are -46.19 , $-393.4,+24.94$ and $-296.9 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. The increasing order of their stability is

• A

  $B \lt D \lt A \lt C$
• Correct answer
  B

  $C \lt A \lt D \lt B$
• C

  $D \lt B \lt C \lt A$
• D

  $A \lt C \lt D \lt B$

Solution

Lower the value of standard enthalpy of formation, higher the stability. The increasing order of standard enthalpies of formation of given molecules is Thus, the increasing order of stability is $C \lt A \lt D \lt B$

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