Redox Reactions And Electrochemistry Question 208
An element A in a compound ABD has oxidation number $ {{A}^{n-}} $ . It is oxidised by $ Cr_2O_7^{2-} $ in acid medium. In the experiment $ 1.68\times {{10}^{-3}} $ moles of $ K_2Cr_2O_7 $ was used for $ 3.26\times {{10}^{-3}} $ moles of ABD. The new oxidation number of A after oxidation is:
Options:
3
3-n
n-3
+n
Show Answer
Answer:
Correct Answer: B
Solution:
Meq. of $ K_2Cr_2O_7=Meq. $ of ABD n-factor of $ K_2Cr_2O_7 $ in acidic medium =6 $ 6\times 1.68\times {{10}^{-3}}=x\times 3.26\times {{10}^{-3}} $ $ x=3.2 $ $ \Rightarrow $ New oxidation state of $ {{A}^{-n}} $ will be =-n-3
 BETA
  BETA 
             
             
           
           
           
          