Which of the following does not participate in the Solvay process for the manufacture of $Na_2CO_3$?

What is the oxidation state of $K$ in $KO_{2}$?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R:$
Assertion $A:$ Metallic sodium dissolves in liquid ammonia giving a deep blue solution,which is paramagnetic.
Reason $R:$ The deep blue solution is due to the formation of amide.
In the light of the above statements,choose the correct answer from the options given below:

Sodium oxide $(Na_2O)$ is produced when

In which of the following processes,fused sodium hydroxide is electrolysed at a $330 \ ^oC$ temperature for the extraction of sodium?

Which of the following is $CORRECT$ regarding alkali metals?
$I$. Pure $NaCl$ is hygroscopic
$II$. $(n - 1)d$ subshell is vacant only
$III$. Aqueous $NaHCO_3$ solution is more basic than $Na_2CO_3$ solution
$IV$. Both $Li^{+}$ and $Mg^{2+}$ do not form alums