Write a balanced equation for the following in a basic solution (should use half-reaction method)

Question

S(s) -> SO3 2-(aq) S 2- (aq)

Answer 1

The easiest way to deal with basic solutions is to balance as if it were acidic using H+ and water and then add enough OH- to both sides to "neutralize" the H+.

S + 3H2O  --> SO3^2- +  6H+  + 4e-

2(S + 2e-  -->  S^2-)

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3S + 3H2O --> SO3^2- + 2S^2- + 6H+

add 6 OH- to both sides

3S + 3H2O + 6OH- -->  SO3^2- + 2S^2- + 6H+ + OH-

simplify

3S + 6OH- -->  SO3^2- + 2S^2- + 3H2O