Which from following formulae is of sodium hexanitrocobaltate(III)?

Which from following formulae is of sodium hexanitrocobaltate(III)?
  1. $\mathrm{Na}_3\left[\mathrm{Co}\left(\mathrm{NO}_2\right)_6\right]$
  2. $\mathrm{Na}_2\left[\mathrm{Co}\left(\mathrm{NO}_2\right)_6\right]$
  3. $\left[\mathrm{Co}\left(\mathrm{NaNO}_2\right)_6\right]$
  4. $\mathrm{Na}_3\left[\mathrm{Co}(\mathrm{ONO})_6\right]$

Solution

The oxidation state of metal ion is +3 . Hence, Sodium hexanitrocobaltate $(\mathrm{III}): \mathrm{Na}_3\left[\mathrm{Co}\left(\mathrm{NO}_2\right)_6\right]$

Asked in: MHT CET 2023 (14 May Shift 1)

Practice more Coordination Compounds questions on Aicharya