JEE Advanced levelSingle correct optionDifficulty 3 of 3ph148
In acidic solution perxenate is reduced to XeOX3, while MnX2+ is oxidised to MnOX4X−. The amount of MnX2+ oxidised by 0.25mol of XeOX6X4− is
A0.050 mol
B0.10 mol
C0.25 mol
D0.625 mol
Answer: B
Xe changes from +8 to +6, so each XeOX6X4− gains 2 electrons; each MnX2+ (+2 to +7) loses 5 electrons. Electrons gained = 0.25×2=0.50mol, so MnX2+ oxidised = 0.50/5=0.10mol (equation: 5XeOX6X4−+2MnX2+5XeOX3+2MnOX4X− in acid).