Redox Reactions And Electrochemistry Ques 549
Question: In the balanced chemical reaction, $ IO_3^{-}+a\ {{I}^{-}}+b\ {{H}^{+}}\to c\ H_2O+d\ I_2 $ a, b, c and d respectively correspond to [AIIMS 2005]
Options:
A) 5, 6, 3, 3
B) 5, 3, 6, 3
C) 3, 5, 3, 6
D) 5, 6, 5, 5
Show Answer
Answer:
Correct Answer: A
Solution:
$IO_3- + aI^- + bH^+ \rightarrow cH_2O + dI_2 $
$Step 1 : I^{-1} \rightarrow I_2 (oxidation) $ $IO_3- \rightarrow I_2 (reduction) $
$Step 2 : 2IO^{3-} + 12H+ \rightarrow I_2 + 6H_2O $
$Step 3 : 2IO3- + 12H+ + 10e \rightarrow I2 + 6H_2O $ $ 2I^- \rightarrow I_2 + 2e $
$Step 4 : 2IO3- + 12H+ + 10e- \rightarrow I2 + 6H_2O $ $[2I^- \rightarrow I_2 + 2e]5 $
$Step 5 : 2IO^{3-} + 10I^- + 12H^+ \rightarrow 6I_2 + 6H_2O $
$IO^{3-} + 5I^- + 6H^+ \rightarrow 3I_2 + 3H_2O $
On comparing, a = 5, b = 6, c = 3, d = 3
