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Assertion:- ZN^(+2) is more polarising t...

Assertion:- `ZN^(+2)` is more polarising than `Mg^(+2)`.
Reason :- A pseudo inert gas configuration `Zn^(+2)` has high `Z_(eff)`, Then inert gas configuration of `Mg^(+2)`

A

If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.

B

If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.

C

If Assertion is True, but the Reason is False.

D

If both Assertion & Reason are false

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze the assertion and reason provided regarding the polarizing power of Zn²⁺ and Mg²⁺ ions. ### Step-by-Step Solution: **Step 1: Understanding Polarizing Power** - Polarizing power refers to the ability of a cation to distort the electron cloud of an anion. The greater the polarizing power, the more it can distort the electron cloud of the anion. **Step 2: Compare the Cations Zn²⁺ and Mg²⁺** - **Zn²⁺ (Zinc ion)**: - Atomic number = 30 - Electronic configuration of neutral Zn = [Ar] 4s² 3d¹⁰ - Upon losing two electrons to form Zn²⁺, the configuration becomes [Ar] 3d¹⁰ (pseudo noble gas configuration). - **Mg²⁺ (Magnesium ion)**: - Atomic number = 12 - Electronic configuration of neutral Mg = [Ne] 3s² - Upon losing two electrons to form Mg²⁺, the configuration becomes [Ne] (noble gas configuration). **Step 3: Effective Nuclear Charge (Z_eff)** - The effective nuclear charge (Z_eff) is the net positive charge experienced by an electron in a multi-electron atom. It accounts for the shielding effect of inner electrons. - Zn²⁺ has a higher Z_eff compared to Mg²⁺ because it has more protons (30) than Mg (12), and the remaining electrons in Zn²⁺ are in a more compact arrangement (3d¹⁰) compared to the full shell of Mg²⁺. **Step 4: Conclusion on Polarizing Power** - Since Zn²⁺ has a higher Z_eff, it has a stronger ability to polarize anions compared to Mg²⁺. Therefore, Zn²⁺ is indeed more polarizing than Mg²⁺. ### Final Answer: - **Assertion**: Zn²⁺ is more polarizing than Mg²⁺. (True) - **Reason**: A pseudo inert gas configuration of Zn²⁺ has a high Z_eff than the inert gas configuration of Mg²⁺. (True) - Both the assertion and reason are correct, and the reason correctly explains the assertion.
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    A
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    B
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    in an ionic bond the cation tends to polarise the electron cloud of the anion by pulling electron density towards itself This causes development of covalent character in the ionic bond because the electron density gets localised in between the nuclei The tendency of the cation to bring about the polarisation of the anion is expressed as its polasising power The ability of ion to undergo polarisation is called its polarisability The polarising power of a cation or an anion is decided on the basis of F ajans' rules as follows . (i) The smaller the cation, the higher is its polarising power (ii) Cations with pseudo-noble gas configuration (ns^(2)np^(6)nd^(10)) have relatively high polarising power than those with noble gas configuration (ns^(2) np^(6)) (iii) The larger the size of the anion, the higher is its polarisability Choose the correct order of polarisability for the following I^(Θ),Br^(Θ),CI^(Θ)F^(Θ) .

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