What mass of hydrogen gas results from the reaction of $8.5 \mathrm{~g}$ of $\mathrm{KH}$ with water?

Why does hydrogen not exhibit an oxidation state of 1 - when bonded to nonmetals?

Why does white phosphorus consist of tetrahedral $\mathrm{P}_4$ molecules while nitrogen consists of diatomic $\mathrm{N}_2$ molecules?

Sodium chloride and strontium chloride are both white solids. How could you distinguish one from the other?

Arrange the following in order of increasing electronegativity: $\mathrm{F} ; \mathrm{Cl} ; \mathrm{O}$; and $\mathrm{S}$.

Determine the oxidation state of sulfur in each of the following: (a) $\mathrm{SO}_3$ (b) $\mathrm{SO}_2$ (c) $\mathrm{SO}_3 2-$

Determine the oxidation number of each element in each of the following compounds: (a) $\mathrm{HCN}$ (b) $\mathrm{OF}_2$ (c) $\mathrm{AsCl}_3$

Write balanced chemical equations for the reaction of the following acid anhydrides with water: (a) $\mathrm{SO}_3$ (b) $\mathrm{N}_2 \mathrm{O}_3$ (c) $\mathrm{Cl}_2 \mathrm{O}_7$ (d) $\mathrm{P}_4 \mathrm{O}_{10}$ (e) $\mathrm{NO}_2$

Nitrogen in the atmosphere exists as very stable diatomic molecules. Why does phosphorus form less stable $\mathrm{P}_4$ molecules instead of $\mathrm{P}_2$ molecules?

Carbon forms a number of allotropes, two of which are graphite and diamond. Silicon has a diamond structure. Why is there no allotrope of silicon with a graphite structure?

Suppose you discovered a diamond completely encased in a silicate rock. How would you chemically free the diamond without harming it?

A hydride of silicon prepared by the reaction of $\mathrm{Mg} 2 \mathrm{Si}$ with acid exerted a pressure of 306 torr at $26^{\circ} \mathrm{C}$ in a bulb with a volume of $57.0 \mathrm{~mL}$. If the mass of the hydride was $0.0861 \mathrm{~g}$, what is its molecular mass? What is the molecular formula for the hydride?

From the data given in Appendix I, determine the standard enthalpy change and the standard free energy change for each of the following reactions: (a) $\mathrm{BF}_3(\mathrm{~g})+3 \mathrm{H}_2 \mathrm{O}(l) \longrightarrow \mathrm{B}(\mathrm{OH})_3(\mathrm{~s})+3 \mathrm{HF}(\mathrm{g})$ (b) $\mathrm{BCl}_3(\mathrm{~g})+3 \mathrm{H}_2 \mathrm{O}(l) \longrightarrow \mathrm{B}(\mathrm{OH})_3(\mathrm{~s})+3 \mathrm{HCl}(\mathrm{g})$ (c) $\mathrm{B}_2 \mathrm{H}_6(\mathrm{~g})+6 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) \longrightarrow 2 \mathrm{~B}(\mathrm{OH})_3(s)+6 \mathrm{H}_2(\mathrm{~g})$

Write a formula for each of the following compounds: (a) silicon dioxide (b) silicon tetraiodide (c) silane (d) silicon carbide (e) magnesium silicide