Hydrogen can be produced by heating

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.

Which of the following substances does not release $O_2$ and acts as a dehydrating agent?

Which of the following statements is not correct?

Which of the following substances is used in the laboratory for fast drying of neutral gases?

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	$(s)$ $H_2O$
	$(t)$ $B_2H_6$