JEE Advanced levelSingle correct optionDifficulty 3 of 3eq031
Bromine disproportionates in hot alkali: 3BrX2+6OHX−5BrX−+BrOX3X−+3HX2O (Br=80). The equivalent mass of BrX2 in this reaction is:
A160
B53.3
C96
D32
Answer: C
For 3 mol BrX2, electrons gained =5 (five BrX− formed), electrons lost =5 (Br→BrOX3X−, 0→+5). Hence the n-factor of BrX2 is 5/3 and equivalent mass =160/(5/3)=96.