Calculate the number of moles of $\mathrm{N}{\mathrm{H}}_4\mathrm{C}\mathrm{l}$ that should be added to one litre of $\text{1.0}\hspace{0.33em}\mathrm{M}\hspace{0.33em}\mathrm{N}{\mathrm{H}}_4\mathrm{O}\mathrm{H}\hspace{0.33em}$ to prepare buffer solution with $\text{pH}\text{=}\text{9}\left[{\text{K}}_{\text{b}}\text{=2}\text{×}{\text{10}}^{-\text{5}}\text{,}\text{take}\text{log}\text{2}\text{=}\text{0}\text{.3}\right]$

• A

  3.4
• B

  2.6
• C

  1.5
• Correct answer
  D

  2

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