In: Chemistry
Determine the oxidation number of P in H3PO3, Mn in KMnO4, Mn in MnO2, N in Ca(NO3)2, O in H2O2.
The general oxidation state of O ( except in peroxides,super oxides & fluorine oxides) is -2
The general oxidation state of H (except in metal hydrides) is +1
The general oxidation state of IA(Li,Na,K,Rb,Cs) elements is +1
The general oxidation state of IIA(Be,Mg,Ca,Sr,Ba) elements is +2
(1) Let a be the oxidation state of P in H3PO3
We know that the sum of the oxidation states of elements in a compound is equal to its charge.
Applying this we have 3(-1) + a + 3(-2) = 0 ( since it is a neutral molecule)
a = +3
Therefore the oxidation state of P in H3PO3 is +3
(2) Let a be the oxidation state of Mn in KMnO4
We know that the sum of the oxidation states of elements in a compound is equal to its charge.
Applying this we have (+1) + a + 4(-2) = 0 ( since it is a neutral molecule)
a = +7
Therefore the oxidation state of Mn in KMnO4 is +7
(3)Let a be the oxidation state of Mn in MnO2
We know that the sum of the oxidation states of elements in a compound is equal to its charge.
Applying this we have a + 2(-2) = 0 ( since it is a neutral molecule)
a = +4
Therefore the oxidation state of Mn in MnO2 is +4
(4) Let a be the oxidation state of N in Ca(NO3)2
We know that the sum of the oxidation states of elements in a compound is equal to its charge.
Applying this we have (+2) +2[ a + 3(-2)] = 0 ( since it is a neutral molecule)
a = +5
Therefore the oxidation state of N in Ca(NO3)2 is +5
(5) Let a be the oxidation state of O in H2O2
We know that the sum of the oxidation states of elements in a compound is equal to its charge.
Applying this we have 2(+1) + 2(a) = 0 ( since it is a neutral molecule)
a = -1
Therefore the oxidation state of O in H2O2 is -1