Question

Identify the correct statements from the following I) \[ \text{Conjugate base of nitrous acid is } NO_2^{-} \] II) \[ \text{The concentration of } OH^{-} \text{ ions in } 0.1\,M \text{ aqueous pyridine solution is } \sqrt{2}\times10^{-5}\,M \] \[ (K_b \text{ of pyridine }=2\times10^{-9}) \] III) The acid strength of aqueous hydrogen halides follows \[ HF \gt HCl \gt HBr \gt HI \]

• A. I, II, III
• B. I, II only
• C. I, III only
• D. II, III only

Hint:

For a weak base: \[ [OH^-]=\sqrt{K_bC} \] and for hydrogen halides in water: \[ HF \lt HCl \lt HBr \lt HI. \] HI is the strongest hydrohalic acid, while HF is the weakest.

Answer 1

The Correct Option is B