Redox Reactions – Solutions

1) Assign oxidation numbers to the underlined elements in each of the following species:

a) NaH₂PO₄ b) NaHSO₄ c) H₄P₂O₇    d) K₂MnO₄   e) CaO₂ f) NaBH₄ g) H₂S₂O₇   

h) KAl(SO₄)₂.12H₂O

Solution

a) +1 +2x -8

NaH₂PO₄

According to oxidation number (ON) rules, sum of all the atoms in an neutral molecule should be zero.

Then,

1+2+x -8=0

So, x=+5