Redox Reactions And Electrochemistry Ques 762
Question: $ 6\times {{10}^{-3}} $ mole $ K_2Cr_2O_7 $ reacts completely with $ 9\times {{10}^{-3}} $ mole of $ {{x}^{n+}} $ to give $ XO_3^{-} $ and $ C{{r}^{3+}} $ . Value of n will be
Options:
A) 1
B) 3
C) 2
D) 4
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ K_2Cr_2O_7+{{X}^{n+}}\xrightarrow[{}]{{}}{{X}^{5+}}O_3^{-}+C{{r}^{3+}} $ $ 6\times {{10}^{-3}}\times 6=(5-n)\times 9\times {{10}^{-3}} $ Implies $ n=1 $ In $ K_2Cr_2O_7 $ oxidation state of $ Cr=6 $ X have change in oxidation number $ =(5-n) $ .
