Question

.Write the electronic configuration of (i) Mn4+, (ii) Fe3+ (iii) Cr2+ and Zn2+ Mention the number of

unpaired electrons in each case.​

Answer 1

$\Large\bigstar{\underline{\red{\sf{Rqeuired\:answers:-}}}}$

(i) Mn⁴⁺

First let us write the configuration of 'Mn' . Manganese has 25 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵

Now , in Mn⁴⁺ Mn has lost 2e⁻ to acquire two units of positive charge. Now , The configuration of Mn⁴⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d³

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d³

three electrons in 3d³ are situated as follows ,

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By the observation , we can say that Mn⁴⁺ has 3 unpaired electrons.

(ii) Fe³⁺

First let us write the configuration of 'Fe' . Iron has 26 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶

Now , in Fe³⁺ Mn has lost 3e⁻ to acquire three units of positive charge. Now , The configuration of Fe³⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d⁵

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵

Five electrons in 3d⁵ are situated as follows ,

$\boxed{ \uparrow \: }\boxed{ \uparrow \: } \boxed{ \uparrow \: }\boxed{\uparrow \: } \boxed{ \uparrow \: } \\ \: \: \: \: \: \: \: \: \: \: \rm \: 3d {}^{5}$

By the observation , we can say that Fe³⁺ has 5 unpaired electrons.

(iii) Cr²⁺

First let us write the configuration of 'Cr' . Chromium has 24 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵

Now , in Cr²⁺ Mn has lost 2e⁻ to acquire two units of positive charge. Now , The configuration of Cr²⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d⁴

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁴

4 electrons in 3d⁴ are situated as follows ,

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By the observation , we can say that Cr²⁺ has 4 unpaired electrons.

(iv) Zn²⁺

First let us write the configuration of 'Zn' . Zinc has 30 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰

Now , in Zn²⁺ . Zn has lost 2e⁻ to acquire two units of positive charge. Now , The configuration of Zn²⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d¹⁰

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰

Five electrons in 3d¹⁰ are situated as follows ,

$\boxed{ \uparrow \downarrow}\boxed{ \uparrow \downarrow } \boxed{ \uparrow \downarrow }\boxed{\uparrow \downarrow} \boxed{ \uparrow \downarrow } \\ \: \: \: \: \: \: \: \: \: \: \rm \: 3d {}^{10}$

By the observation , we can say that Zn²⁺ has 0 unpaired electrons.

Answer 2

Answer:

\Large\bigstar{\underline{\red{\sf{Rqeuired\:answers:-}}}}★

Rqeuiredanswers:−

(i) Mn⁴⁺

First let us write the configuration of 'Mn' . Manganese has 25 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵

Now , in Mn⁴⁺ Mn has lost 2e⁻ to acquire two units of positive charge. Now , The configuration of Mn⁴⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d³

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d³

three electrons in 3d³ are situated as follows ,

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By the observation , we can say that Mn⁴⁺ has 3 unpaired electrons.

(ii) Fe³⁺

First let us write the configuration of 'Fe' . Iron has 26 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶

Now , in Fe³⁺ Mn has lost 3e⁻ to acquire three units of positive charge. Now , The configuration of Fe³⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d⁵

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵

Five electrons in 3d⁵ are situated as follows ,

\begin{gathered} \boxed{ \uparrow \: }\boxed{ \uparrow \: } \boxed{ \uparrow \: }\boxed{\uparrow \: } \boxed{ \uparrow \: } \\ \: \: \: \: \: \: \: \: \: \: \rm \: 3d {}^{5} \end{gathered}

↑

↑

↑

↑

↑

3d

5

By the observation , we can say that Fe³⁺ has 5 unpaired electrons.

(iii) Cr²⁺

First let us write the configuration of 'Cr' . Chromium has 24 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵

Now , in Cr²⁺ Mn has lost 2e⁻ to acquire two units of positive charge. Now , The configuration of Cr²⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d⁴

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁴

4 electrons in 3d⁴ are situated as follows ,

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By the observation , we can say that Cr²⁺ has 4 unpaired electrons.

(iv) Zn²⁺

First let us write the configuration of 'Zn' . Zinc has 30 electrons

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰

Now , in Zn²⁺ . Zn has lost 2e⁻ to acquire two units of positive charge. Now , The configuration of Zn²⁺ is ,

1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d¹⁰

= 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰

Five electrons in 3d¹⁰ are situated as follows ,

\begin{gathered} \boxed{ \uparrow \downarrow}\boxed{ \uparrow \downarrow } \boxed{ \uparrow \downarrow }\boxed{\uparrow \downarrow} \boxed{ \uparrow \downarrow } \\ \: \: \: \: \: \: \: \: \: \: \rm \: 3d {}^{10} \end{gathered}

↑↓

↑↓

↑↓

↑↓

↑↓

3d

10

By the observation , we can say that Zn²⁺ has 0 unpaired electrons.