Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. What is the value of $n$ in the following half equation? $Cr ( OH )_{4}^{-}+ OH \rightarrow CrO _{4}^{2-}+ H _{2} O +n e^{-}$

Redox Reactions

Solution:

$ Cr ( OH )_{4}^{-}+ OH ^{-} \rightarrow CrO _{4}^{2-}+ H _{2} O$

Writing oxidation states, we have $\left[ Cr ( OH )_{4}\right]^{-}+ OH ^{-} \rightarrow\left[ CrO _{4}\right]^{2-}+ H _{2} O$

To balance oxidation state of $Cr$ on both sides, add $3 e^{-}$ on $R. H.S$.