Which of the following arrangements represent the increasing oxidation number of the central atom?
CrO−2,ClO−3,CrO2−4,MnO−4
CrO−2
Let oxidation number of Cr be a
a+2×(−2)=−1
a−4=−1
Oxidation number of Cr is +3
ClO−3
Let oxidation number of Cl be b
b+3×(−2)=−1
b−6=−1
b=+5
Oxidation number of Cl is +5.
CrO2−4
Let oxidation number of Cr be c
c+4×(−2)=−2
c−8=−2
c=+6
Oxidation number of Cr is +6.
MnO−4
Let oxidation number of Mn be d
d+4×(−2)=−1
d−8=−1
d=+7
Oxidation number of Mn is +7
CrO−2(Cr=+3),ClO−3(Cl=+5),
CrO2−4(Cr=+6),MnO−4(Mn=+7)
Thus, order is:
CrO−2,ClO−3,CrO2−4,MnO−4
Hence, correct answer is option (A).