Question

The correct order of oxidising power is : $VO_2^+$ $< Cr_2O_7^{2-} < MnO_4^-$ The oxidation state of $Mn$ is $+7$.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

If both assertion and reason are true but reason is not the correct explanation of assertion

Answer 2

The oxidation states of the given compounds are VO$_{2}^{+}$ : x + 2(-2) = +1 $\Rightarrow$ x = +5 CrO$_{7}^{2-}$ : 2x + 7(-2) = -2 $\Rightarrow$ 2x = +12 $\Rightarrow$ x = +6 MnO$_{4}^{-}$ : x + 4(-2) = -1 $\quad \quad \quad$ x = -1 + 8 = + 7 The correct order of oxidising power is VO$_{2}^{+}$ < CrO$_{7}^{2-}$ < MnO$_{4}^{-}$ due to the increasing stability of the lower species to which they are reduced.