91Ó°ÊÓ

A solid cube of ammonia floats in liquid ammonia. Which is more dense: solid or liquid ammonia?

Without referring to Table 6 , predict which compound in each of the following pairs has the higher melting point: (a) \(\mathrm{H}_{2} \mathrm{O}\) or \(\mathrm{H}_{2} \mathrm{~S}\) (b) \(\mathrm{H}_{2} \mathrm{~S}\) or \(\mathrm{H}_{2} \mathrm{Se}\)

Without referring to Table \(6,\) predict which compound in each of the following pairs has the higher boiling point: (a) \(\mathrm{H}_{2} \mathrm{O}\) or \(\mathrm{H}_{2} \mathrm{Se}\) (b) \(\mathrm{H}_{2} \mathrm{~S}\) or \(\mathrm{H}_{2} \mathrm{Te}\)

Without referring to Table \(6,\) predict which compound in each of the following pairs has the higher heat of fusion \((\mathrm{cal} / \mathrm{mol}):\) (a) \(\mathrm{H}_{2} \mathrm{O}\) or \(\mathrm{H}_{2} \mathrm{~S}\) (b) \(\mathrm{H}_{2} \mathrm{~S}\) or \(\mathrm{H}_{2} \mathrm{Se}\)

Without referring to Table \(6,\) predict which compound in each of the following pairs has the higher heat of vaporization (cal/mol): (a) \(\mathrm{H}_{2} \mathrm{O}\) or \(\mathrm{H}_{2} \mathrm{Se}\) (b) \(\mathrm{H}_{2} \mathrm{~S}\) or \(\mathrm{H}_{2} \mathrm{Te}\)

In general, as the molar mass of Group VIA/16 hydrogen compounds increases, does each of the following increase or decrease? (a) melting point (b) boiling point (c) heat of fusion (d) heat of vaporization

Write a balanced equation for the reaction of hydrogen and oxygen gases.

Complete and balance the following equations: (a) \(\mathrm{Li}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (b) \(\mathrm{Na}_{2} \mathrm{O}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (c) \(\mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\)

Complete and balance the following equations: (a) \(\mathrm{Rb}(s)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (b) \(\mathrm{Cs}_{2} \mathrm{O}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (c) \(\mathrm{P}_{2} \mathrm{O}_{5}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\)

Complete and balance the following equations: (a) \(\mathrm{Mg}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (b) \(\operatorname{SrO}(s)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (c) \(\mathrm{N}_{2} \mathrm{O}_{5}(g)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\)