Colourless salt (A) gives white ppt (B) with NaOH; ppt (B) dissolves in excess of NaOH to form (C). On passing H2S gas into (A) solution white ppt (D) appears. (A) also gives white ppt (E) with AgNO3 solution.
Which of the following is compound B?
Answer & explanation
Correct answer: option 2
Zinc (II) ion such as one present in zinc nitrate reacts with sodium hydroxide to form sodium nitrate and a white precipitate of zinc hydroxide.
2NaOH+ZnCl2 → 2NaCl + white precipitate Zn(OH)2
2NaOH+ZnCl2 → 2NaCl + white precipitate Zn(OH)2