This question is about different structures of group 14 oxides: silicon dioxide (SiO2\text{SiO}_2SiO2) and carbon dioxide (CO2\text{CO}_2CO2).
Name the type of chemical bond that exists between the atoms within both silicon dioxide and carbon dioxide.
Explain, in terms of structure and bonding, why silicon dioxide has a very high melting point.
Carbon dioxide has a simple molecular structure. Explain why it has a very low sublimation temperature.
Cristobalite and quartz are two different crystalline forms of silica. They can be interconverted according to the equation:
SiO2(cristobalite)⇌SiO2(quartz)ΔH=−1.5 kJ/mol \text{SiO}_2(\text{cristobalite}) \rightleftharpoons \text{SiO}_2(\text{quartz}) \quad \Delta H = -1.5 \text{ kJ/mol} SiO2(cristobalite)⇌SiO2(quartz)ΔH=−1.5 kJ/molWould a low or a high temperature favour the conversion of cristobalite into quartz? Give a reason for your choice.
