Dehydration of oxalic acid with concentrated $H_2SO_4$ produces ............

Match the correct option from Column-$A$ and Column-$B$.

Column-$A$	Column-$B$
$(1)$ Ionic hydride	$(p)$ $BeH_2$
$(2)$ Interstitial hydride	$(q)$ $TiH$
$(3)$ Electron-precise hydride	$(r)$ $CH_4$
$(4)$ Electron-rich hydride	$(s)$ $H_2O$
	$(t)$ $B_2H_6$

$2BeCl_2 + LiAlH_4 \rightarrow X + LiCl + AlCl_3$

In which of the following reactions,hydrogen is acting as an oxidising agent?

Identify the correct statements from the following:
$(I)$ The formula of Calgon is $Na_6(PO_3)_6$.
$(II)$ Exhausted permutit is regenerated by aqueous $KCl$ solution.
$(III)$ Calcium stearate is soluble in water.
$(IV)$ In ice crystals,each oxygen is surrounded by four oxygen atoms.

Ordinary hydrogen at room temperature is a mixture of