Consider the reactions shown below. 5 Fe2+ + MnO4- + 8 H+ ---> 5 Fe3+ + Mn2+ + 4 H2O and 5 NO2- + 2 MnO4- + 6

Question

Consider the reactions shown below.

5 Fe2+ + MnO4- + 8 H+ ---> 5 Fe3+ + Mn2+ + 4 H2O
5 NO2- + 2 MnO4- + 6 H+ ---> 2 Mn2+ + 5 NO3- + 3 H2O

a) What is the molarity of KMnO4(aq) if 25.55 mL KMnO4(aq) is required to titrate 14.00 mL of 0.2334 M FeSO4(aq)?

b) What is the molarity of KMnO4(aq) if a 552.4 mg sample of KNO2 requires 32.61 mL KMnO4(aq) for its titration?

Answer 1

I like to write the reactions clearly as follows:
5Fe(2+) + MnO4(-) + 8H(+) ---> 5Fe(3+) + Mn(2+) + 4H2O
5NO2(-) + 2MnO4(-) + 6H(+) ---> 2Mn(2+) + 5NO3(-) + 3H2O
(a) 0.014*0.2334 = 5*0.02555*[KMnO4(aq)]
You do the math to find [KMnO4(aq)].
(b) With the molar mass of KNO2 to be: 85.1038g/Mol, we have: 
0.5524/(85.1038*5) = 0.03261*[KMnO4(aq)] /2
You do the math to find [KMnO4(aq)].

Answer 2

Mn is going from +7 on the left to +2 on the main suitable area. this is been decreased. this is the oxidizing agent. Fe is going from +2 on the left to +3 on the main suitable. this is been oxidized. this is the reducing agent.