General Chemistry

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<h3>Explain the Lewis structure of I3- ion which involves hypervalence.</h3>

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Explaining the Lewis Structure of I3&minus;​ Ion Involving Hypervalence

The I3&minus;​ ion, also known as the triiodide ion, is an interesting and somewhat unusual species.

To understand its Lewis structure, we must first understand the concept of hypervalence.

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Step 1: Understand Hypervalence

<ul>
	<li>Hypervalence refers to molecules and ions that contain atoms with more than an octet of electrons around them.</li>
	<li>This phenomenon is commonly observed in elements from the third period and beyond on the periodic table, as they have access to d-orbitals which can participate in bonding.</li>
</ul>

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Step 2: Counting Valence Electrons

<ul>
	<li>To draw the Lewis structure, we first need to count the total number of valence electrons.</li>
	<li>Iodine (I) has 7 valence electrons, and since there are three iodine atoms, we have 3&times;7=21 electrons.</li>
	<li>The extra electron from the negative charge gives us a total of 22 valence electrons.</li>
</ul>

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Step 3: Initial Bonding

<ul>
	<li>Two of the iodine atoms will bond together, using up 2 electrons.</li>
	<li>The third iodine atom will also bond to one of the other iodine atoms, using up another 2 electrons.</li>
	<li>This leaves us with 18 electrons.</li>
</ul>

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<img alt="" src="data:image/png;base64,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" style="width: 150px; height: 44px;" />

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Step 4: Distributing Remaining Electrons

<ul>
	<li>The remaining 18 electrons will be distributed as lone pairs.</li>
	<li>Each iodine atom will get three lone pairs (6 electrons), using up a total of 18 electrons.</li>
</ul>

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<img alt="" src="data:image/png;base64,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" style="width: 150px; height: 57px;" />

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Step 5: Hypervalence in I3&minus;​

<ul>
	<li>The central iodine atom is surrounded by more than 8 electrons, making it hypervalent.</li>
	<li>It is surrounded by 10 electrons: 2 from the bond with one iodine, 2 from the bond with the other iodine, and 6 non-bonding electrons.</li>
	<li>This is possible because iodine can utilize its available d-orbitals for bonding, allowing it to exceed the octet rule.</li>
</ul>

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Step 6: Final Structure

The Lewis structure can be represented as:

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<img alt="I_3^- Lewis structure" src="data:image/png;base64,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" style="width: 170px; height: 51px;" />

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With each iodine atom having three lone pairs and the entire structure carrying a negative charge.

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Summary:

<ul>
	<li>The I3&minus;​ ion is a linear molecule with a central hypervalent iodine atom bonded to two other iodine atoms.</li>
	<li>The central iodine atom exceeds the octet rule due to the availability of d-orbitals, allowing it to accommodate more than 8 electrons.</li>
	<li>This is a classic example of hypervalence in action, showcasing the fascinating and sometimes unexpected ways in which elements can bond and form stable structures.</li>
</ul>

Question

Explain the Lewis structure of I3^- ion which involves hypervalence.

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