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The d & f Block Elements — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryThe d & f Block Elements3 Marks
Question
Identify the metal and justify your answer.
  1. Carbonyl M $(CO)_5$
  2. $MO_3F$
✓

Answer

It is $=0$
$x=+7 M$ is in +7 oxidation state so that the given compound is $\mathrm{MnO}_3 \mathrm{~F}$
i. $\mathrm{Fe}(\mathrm{CO})_5$ by EAN rule
EAN $=x+2 \times 5=36(\mathrm{Kr}$ is the nearest inert gas)
$x=26$ (atomic no. of the metal) so the metal is iron.
ii. $\mathrm{MO}_3 \mathrm{~F}$ is $\mathrm{MnO}_3 \mathrm{~F}$
In $\mathrm{MO}_3 \mathrm{~F}$ let us assume $\mathrm{M}=\mathrm{x}$
$x+3 \times(-2)+(-1)$
$x=+7$
M is in + 7 osidation state so that the given compound is $\mathrm{MnO}_3 \mathrm{~F}$

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