JEE Advanced levelSingle correct optionDifficulty 3 of 3qc217
A solution containing 0.535g of NHX4Cl is boiled with excess NaOH, and the ammonia evolved is absorbed completely in excess Nessler's reagent. The brown product is HgO⋅Hg(NHX2)I (molar mass 559g/mol; NHX4Cl is 53.5g/mol, one product unit per N). The mass of brown solid is
A11.2g
B2.80g
C0.559g
D5.59g
Answer: D
Moles of NHX4Cl = 0.535/53.5=0.0100, giving 0.0100 mol NHX3 and so 0.0100 mol of the iodide of Millon's base. Mass = 0.0100×559=5.59g.