Question

Assertion (A): If aluminium atoms replace a few silicon atoms in three dimensional network of silicon dioxide, the overall structure acquires a negative charge.

Reason (R): Aluminium is trivalent while silicon is tetravalent.

• A. $A$ is not correct but $R$ is correct.
• B. Both $A$ and $R$ are correct and $R$ is not the correct explanation of $A$.
• C. Both $A$ and $R$ are not correct
• D. Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$

Answer 1

The correct option is D Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$

$\text{Analysing the assertion}:$

If Aluminium atoms replace a few silicon atoms in a $3D$ network of silicon dioxide, the overall structure acquires a negative charge. Yes, it is true statement.

$\text{Analysing the reason}:$

In aluminosilicates (anion), some of the silicon atoms are replaced by aluminium. Since, aluminium is trivalent while silicon is tetravalent, hence we get negatively charged ion.


Hence, reason $\left(R\right)$ is true and it is the correct explanation of assertion.

So, correct answer is option $\left(A\right)$.