Pls solbe this questions .Please write the reactiom also

Thanks

 MnO₂   +             4HCl       →           MnCl₂                +             Cl₂

Cl₂        +             2KI          →           2KCl                   +             I₂

I₂         +             2Na₂S₂O₃ →        2NaI                      +             Na₂S₄O₆

Redox change are :

2e           +             I₂           →           2I^-

2(S²⁺)₂                                 →           (S^5/2+)₄ +             2e

2e           +             Mn⁴⁺      →           Mn²⁺

The above reaction suggest that,

Meq. of MnO₂                   =             Meq. of Cl₂formed

=             Meq. of I₂ liberated    

=             Meq. of Na₂S₂O₃ used

Therefore,          [w/(M/2)] × 1000             =             0.1 × 1 × 30

[ NNa₂S₂O₃= MNa₂S₂O₃, as, valency factor = 1]

Or,         w            =             (0.1 × 1 × 30 × M)/200

=             (0.1 × 1 × 30 × 87)/200

=             0.1305

Therefore,          Purity of MnO₂                  =             (0.1305/0.5) × 100

=             26.1%