Question {Neet 2015 PYQ} Redox Reaction

Question. Assuming complete ionization, same moles of which of the following compounds will require the least amount of acidified KMnO4 for complete oxidation?

A. FeC2O4

B. Fe(NO2)2

C. FeSO4

D. FeSO3

C

Solution. Option C is Correct. MnO4 − ⟶ Mn2+ ; Change in oxidation no. = 5 In option, i. Fe2+ ⟶ Fe3+ Change in oxidation no. = 1 ii. Fe2+ ⟶ Fe3+ Change in oxidation no. = 1 SO3 2− ⟶ SO4 2− Change in oxidation no. = 2 = 1 + 2 = 3 iii. Fe2+ ⟶ Fe3+ Change in oxidation no. = 1 C2O4 2− ⟶ 2CO2 Change in oxidation no. = 2 = 1 + 2 = 3 iv. Fe2+ ⟶ Fe3+ Change in oxidation no. = 1 2NO2 − ⟶ 2NO3 − Change in oxidation no. = 4 = 1 + 4 = 5

Related Question. 

A mass of 1kg is thrown up with a velocity of 100m/s. After 5 seconds, it explodes into two parts. One part of mass 400g comes down with a velocity 25m/s . The velocity of other part is (Take g= 9.8m/s²)