Question

Balance the following chemical equation under basic conditions and provide the coefficients

SO₄^2-(aq) +I^-(aq) --> SO₃^2-(aq) + I₃^-(aq)

The coefficient for SO₄^2- is _____

The coefficient for I^- is __________

The coefficient for SO₃^2- is _________

The coefficient for I₃^- is _________

The coefficient for H₂O _____ on the ______ side (*type either: product or reactant)

The coefficient for OH^- is _______ on the ________ side (*type either: product or reactant)

Answer 1

SO42-(aq) +I-(aq) --> SO32-(aq) + I3-(aq)

SO4^2- is converting to SO3^2- so oxidation state is changing from (+6) to (+4) i.e reduction

x - 8 = -2 x - 6 = -2

x = -2 + 8 = +6 x = -2 + 6 = + 4

Oxidation Half cell

SO3^2-(aq) + 2OH- =>   SO4^2-(aq) - 2e- + H2O    (Balanced Reduction half cell) .....(1)

Reduction Half cell

I-(aq) + 2e-   -->    I3-(aq) (2)

subtract (2) - (1)

I-(aq) + 2e- - SO3^2-(aq) - 2OH- => I3-(aq) - SO4^2-(aq) + 2e- - H2O

Hence on solving complete balanced chemical equation is as follows:

  I-(aq) + SO4^2-(aq) + H2O =>  I3-(aq) + SO3^2-(aq) + 2OH-

So The coefficient for SO42- is 1

The coefficient for I- is 1

  The coefficient for SO32- is 1

  The coefficient for H2O is 1 on the left side.

  The coefficient for OH- is 2 on the right side.