Show by a chemical reaction with water that $Na_{2}O$ is a basic oxide and $Cl_{2}O_{7}$ is an acidic oxide.

(N/A) $Na_{2}O$ reacts with water to form a strong base,while $Cl_{2}O_{7}$ reacts with water to form a strong acid.
$Na_{2}O + H_{2}O \rightarrow 2NaOH$
$Cl_{2}O_{7} + H_{2}O \rightarrow 2HClO_{4}$
These reactions demonstrate that $Na_{2}O$ is a basic oxide and $Cl_{2}O_{7}$ is an acidic oxide,which can be confirmed using litmus paper.