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4. d and f- block elements — Chemistry STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceChemistry4. d and f- block elements1 Mark
MCQ
What changes does not occur when $K_2Cr_2O_7$ react with $H_2O_2$ solution
  • A
    Orange colour of solution turns blue
  • ✓
    $O.S.$ of $Cr$ atom decreases
  • C
    $O.S.$ of $Cr$ atom remains constant
  • D
    None of these
✓

Answer

Correct option: B.
$O.S.$ of $Cr$ atom decreases
b
$\mathop {{K_2}C{r_2}{O_7}}\limits_{\left( { + 6} \right)}  + {H_2}{O_2} \to \mathop {\mathop {Cr{O_5}}\limits^{\left( { + 6} \right)} }\limits_{\left( {Blue\,Chromate} \right)} $

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