Question

Which of the following oxide is most acidic?
(a)- $N{{a}_{2}}O$
(b)- $MgO$
(c)- $Si{{O}_{2}}$
(d)- $C{{l}_{2}}{{O}_{7}}$

Answer 1

When we move along the period from left to right, then the basic character of the elements decreases, and the acidic character increases, so we can say that the oxide of metals are basic and oxides of non-metals are acidic.

Complete step by step answer:
We know that there are various properties of the elements along the period and along with the group. These properties have trended throughout the period and along with the group.
So we know that in the periodic table the metal is placed on the left side of the table and towards moving right the metallic character decreases and the non-metallic character increases, or we can say that non-metals are towards the right side of the table.
In the same way, while moving along the period from left to right the basic character decreases, and the acidic character increases.
We know that sodium and magnesium are metals and places in group 1 and group 2 respectively, so their oxides will be basic. Therefore, $N{{a}_{2}}O$ and $MgO$ are basic or we can say that they are basic oxides.
Now both sulfur and chlorine are non-metals, but sulfur is the element of group 16 and chlorine is the element of group 17, so chlorine is more non-metallic than sulfur or chlorine is more acidic than sulfur. So, $C{{l}_{2}}{{O}_{7}}$ is more acidic than $Si{{O}_{2}}$.

So, the correct answer is an option (d)- $C{{l}_{2}}{{O}_{7}}$.

Note: When $C{{l}_{2}}{{O}_{7}}$reacts with water, it forms Perchloric acid having formula $HCl{{O}_{4}}$, which is a very strong acid. The reaction is given below:
$C{{l}_{2}}{{O}_{7}}+{{H}_{2}}O\to 2HCl{{O}_{4}}$.