18.3 Structure and General Properties of the Metalloids

Using only the periodic table, write the complete electron configuration for silicon, including any empty orbitals in the valence shell. You may wish to review the chapter on electronic structure.

Describe the hybridization of silicon and the molecular structure of the following molecules and ions:

(a) (CH₃)₃SiH

(b) $\text{SiO}_{4} ^{4−}$

(c) Si₂H₆

(d) Si(OH)₄

(e) $\text{SiF}_{6} ^{2−}$

Classify each of the following molecules as polar or nonpolar. You may wish to review the chapter on chemical bonding.

(a) SiH₄

(b) Si₂H₆

(c) SiCl₃H

(d) SiF₄

(e) SiCl₂F₂

Name each of the following compounds:

(a) TeO₂

(b) Sb₂S₃

(c) GeF₄

(d) SiH₄

(e) GeH₄

Why is boron limited to a maximum coordination number of four in its compounds?

From the data given in Appendix G, determine the standard enthalpy change and the standard free energy change for each of the following reactions:

(a) $\text{BF}_{3} \left(g\right) + \text{3H}_{2} \text{O} \left(l\right) \rightarrow \text{B} \left(\text{OH}\right)_{3} \left(s\right) + \text{3HF} \left(g\right)$

(b) $\text{BCl}_{3} \left(g\right) + \text{3H}_{2} \text{O} \left(l\right) \rightarrow \text{B} \left(\text{OH}\right)_{3} \left(s\right) + \text{3HCl} \left(g\right)$

(c) $\text{B}_{2} \text{H}_{6} \left(g\right) + \text{6H}_{2} \text{O} \left(l\right) \rightarrow \text{2B} \left(\text{OH}\right)_{3} \left(s\right) + \text{6H}_{2} \left(g\right)$

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