Exercise 3 | Oxidation-Reduction Reactions

Determine what particle is being oxidized and which is being reduced in the following reactions:


1) Cr+ + Sn4+ → Cr3+ + Sn2+

2) Ca + F2 → CaF2

3) MgO (s) + C (s) → Mg (s) + CO (g)

1) oxidation states: Cr+ = +1; Cr3+ = +3; Sn4+ = +4; Sn2+ = +2

Cr+ is oxidized, Sn4+ is reduced

 

2) oxidation states: Ca = 0; F in F2 = 0; Ca in CaF2 = +2, F in CaF2 = -1

Ca is oxidized, F2 is reduced

 

3) oxidation states: Mg in MgO = +2; C = 0; Mg = 0; C in CO = +2

MgO is reduced, C is oxidized