Among the following oxides of p-block elements, number of oxides having amphoteric nature is ________.
$\mathrm{Cl}_2 \mathrm{O}_7, \mathrm{CO}, \mathrm{PbO}_2, \mathrm{~N}_2 \mathrm{O}, \mathrm{NO}, \mathrm{Al}_2 \mathrm{O}_3, \mathrm{SiO}_2, \mathrm{~N}_2 \mathrm{O}_5, \mathrm{SnO}_2$
Answer (integer)
3
Solution
<p>An amphoteric oxide is one that displays both acidic and basic properties; such substances react with both acids and bases. In the p-block, several elements can form amphoteric oxides, particularly those elements that are metallic or metalloid in nature. It's essential to recognize which oxides among the provided list have an amphoteric character:</p>
<ul>
<li>$\mathrm{Cl}_2 \mathrm{O}_7$ - This is dichlorine heptoxide, an oxide of chlorine, and shows acidic properties. It is not amphoteric.</li>
<li>$\mathrm{CO}$ - Carbon monoxide does not behave as an acidic or basic oxide; it is mainly a neutral oxide.</li>
<li>$\mathrm{PbO}_2$ - Lead(IV) oxide, also known as plumbic oxide. This oxide of lead is amphoteric, but it is much less common and less amphoteric than lead(II) oxide, PbO.</li>
<li>$\mathrm{N}_2 \mathrm{O}$ - Nitrous oxide is a neutral oxide; it does not exhibit acidic or basic properties.</li>
<li>$\mathrm{NO}$ - Nitric oxide, like N2O, is a neutral oxide.</li>
<li>$\mathrm{Al}_2 \mathrm{O}_3$ - Aluminium oxide is well known for being amphoteric. It reacts with both acids and bases to produce salts and water.</li>
<li>$\mathrm{SiO}_2$ - Silicon dioxide is generally acidic. Although it does not react with water to form an acidic solution, it will react with basic oxides. Therefore, it is typically not considered amphoteric.</li>
<li>$\mathrm{N}_2 \mathrm{O}_5$ - Dinitrogen pentoxide is an acidic oxide; it is the anhydride of nitric acid.</li>
<li>$\mathrm{SnO}_2$ - Tin dioxide, also known as stannic oxide. This oxide of tin is amphoteric, reacting with both acids and bases.</li>
</ul>
<p>From the list, the amphoteric oxides are:</p>
<ul>
<li>$\mathrm{PbO}_2$ - Lead(IV) oxide (less commonly amphoteric compared to PbO)</li>
<li>$\mathrm{Al}_2 \mathrm{O}_3$ - Aluminium oxide</li>
<li>$\mathrm{SnO}_2$ - Tin dioxide</li>
</ul>
<p>So, the number of amphoteric oxides in the list provided is 3.</p>
About this question
Subject: Chemistry · Chapter: p-Block Elements · Topic: Group 13: Boron Family
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