JEE MAIN - Chemistry (2023 - 29th January Evening Shift - No. 8)

Correct order of spin only magnetic moment of the following complex ions is :

(Given At.no. Fe : 26, Co : 27)

$$\mathrm{[CoF_6]^{3-} > [FeF_6]^{3-} > [Co(C_2O_4)_3]^{3-}}$$

$$\mathrm{[FeF_6]^{3-} > [Co(C_2O_4)_3]^{3-} > [CoF_6]^{3-}}$$

$$\mathrm{[FeF_6]^{3-} > [CoF_6]^{3-} > [Co(C_2O_4)_3]^{3-}}$$

$$\mathrm{[Co(C_2O_4)_3]^{3-} > [CoF_6]^{3-} > [FeF_6]^{3-}}$$

$${\left[ {Fe{F_6}} \right]^{3 - }}\buildrel {} \over \longrightarrow 5$$ unpaired electrons

$${\left[ {Co{{\left( {{C_2}{O_4}} \right)}_3}} \right]^{3 - }}\buildrel {} \over \longrightarrow 0$$ unpaired electron

$${\left[ {Co{F_6}} \right]^{3 - }}\buildrel {} \over \longrightarrow 4$$ unpaired electrons

So, correct answer is : (3)