State the total number of valence electrons in one molecule of $PCl_3$.

Draw the Lewis formula of $PCl_3$, showing all bonding pairs and lone pairs.

State whether the phosphorus atom obeys the octet rule in this molecule.

State the bond order of the carbon-carbon bond in ethyne, $HC\equiv CH$.

Explain the relationship between bond order, bond length and bond strength for carbon-carbon bonds.

Compare the bonding and arrangement of carbon atoms in diamond and graphite.

Explain why graphite conducts electricity but diamond does not.

State the strongest intermolecular force between propanone molecules.

Explain why propanone is much more soluble in water than butane.

State why London dispersion forces are present in both substances.

State the number of sigma bonds and pi bonds in one molecule of propyne.

Explain why a sigma bond is usually stronger than a pi bond.

State the total number of valence electrons in $OF_2$.

Identify the electron-deficient molecule in the panel.

Explain why the central atom in $NH_4^+$ has no lone pair, although the central atom in $NH_3$ does.

State the bond order of the carbon-carbon bond with the shortest bond length.

Describe the relationship between carbon-carbon bond length and average bond enthalpy shown by the data.

Explain why a carbon-carbon triple bond is stronger than a carbon-carbon single bond.

Deduce the number of electron domains around the carbon atom and the electron domain geometry.

Suggest why the $H-C-H$ bond angle is slightly less than the ideal angle for this electron domain geometry.

Deduce whether methanal is polar.

Calculate the $R_F$ value for spot X.

Explain which compound, X or Y, is less polar.

State what is meant by resonance structures.

Deduce the number of equivalent resonance structures for $CO_3^{2-}$.

Explain why the three carbon-oxygen bonds in $CO_3^{2-}$ have the same length.

Deduce the electron domain geometry and molecular geometry around sulfur in $SF_4$.

Explain why the lone pair in $SF_4$ is placed in an equatorial position in the VSEPR model.

State the molecular geometry of $XeF_4$.

Deduce the molecular geometry of $NH_3$ from the data.

Compare the bond angles in $CH_4$, $NH_3$ and $H_2O$ using the VSEPR model.

Suggest why the $H-C-H$ angle in $H_2CO$ is less than the ideal trigonal planar angle.

Identify the substance that conducts electricity well along layers and can act as a lubricant.

Explain the high melting point of silicon dioxide.

Suggest why buckminsterfullerene has a much lower melting point than diamond.

Identify the substance most likely to form hydrogen bonds between its own molecules.

Explain why the alcohol has a higher boiling point than the ether, although their molar masses are similar.

Suggest why the hydrocarbon has the lowest solubility in water.

State what the equal $C-O$ bond lengths in $CO_3^{2-}$ indicate about the three bonds.

Explain why a single Lewis formula with one $C=O$ bond and two $C-O$ bonds does not fully represent $CO_3^{2-}$.

Deduce the average bond order of each carbon-oxygen bond in $CO_3^{2-}$.

Deduce the molecular geometry of a species with five electron domains, four bonding domains and one lone pair.

Explain why the lone pair in $SF_4$ occupies an equatorial position in a trigonal bipyramidal electron domain geometry.

Deduce the molecular geometry of $XeF_4$.

State the geometry around each carbon atom in benzene.

Explain how carbon-carbon bond length data support the delocalized model of benzene.

Suggest why benzene tends to undergo substitution rather than addition reactions.

Calculate the formal charge on oxygen in formula A.

Calculate the formal charge on nitrogen in formula B.

Deduce which formula is preferred, using formal charge arguments.

State the hybridization and electron domain geometry of the carbon atom in the carboxylate group.

Explain why the two carbon-oxygen bonds in the carboxylate group are equal in length.

Calculate the $R_F$ value of the dye spot in the mixture that travelled $3.2\ \text{cm}$ when the solvent front travelled $8.0\ \text{cm}$.

Identify which reference dye matches the mixture spot with $R_F=0.40$.

Suggest why the most polar dye travels the shortest distance on this TLC plate.

Calculate the formal charge on oxygen in structure A.

Calculate the formal charge on nitrogen in structure B.

Determine which structure is preferred using formal charge arguments.

Deduce the number of sigma bonds and pi bonds in the displayed resonance structure.

Explain why the measured $N-O$ bonds in nitrate are equal, although the displayed structure contains one double bond and two single bonds.

Suggest why the measured $N-O$ bond length is intermediate between typical single and double $N-O$ bond lengths.

Deduce the hybridization of $C_1$ and $C_3$.

Explain the linear geometry around $C_3$ in terms of hybridization.

Analyse the pi bonding in acrylonitrile.

Explain why the H-C-H bond angle in methanal is slightly less than the ideal angle for its electron domain geometry.

Methanal contains polar C=O bonds and polar C-H bonds. Explain whether methanal is polar overall.

Draw the Lewis formula of $H_3NBF_3$, using an arrow to show the coordination bond.

Explain why $BF_3$ can accept an electron pair even though each fluorine atom has an octet.

Use the data to analyse the relationship between bond order, bond length and bond strength.

Evaluate the statement: “A molecule containing a triple bond is always less reactive than a molecule containing a single bond because the triple bond is stronger.”

Explain which compound is most strongly attracted to the stationary phase.

Evaluate why $R_F$ values from this experiment should not be used to identify compounds unless the chromatography conditions are specified.

Calculate the resonance energy of benzene using a hypothetical hydrogenation enthalpy of $-360\ \text{kJ mol}^{-1}$ and an experimental value for benzene of $-208\ \text{kJ mol}^{-1}$.

State how the carbon-carbon bond length data support delocalization in benzene.

Discuss why benzene tends to undergo substitution rather than addition reactions.

Compare the bonding around carbon atoms in diamond and graphite.

Explain why graphite conducts electricity but silicon dioxide does not.

Deduce the strongest type of intermolecular force between molecules of each substance.

Discuss why molar mass alone is not sufficient to predict the volatility of these compounds.

Calculate the bond order of each O-O bond in ozone using the resonance model.

Oxygen, $O_2$, and ozone absorb different wavelengths of ultraviolet radiation in the atmosphere. Explain why different photon energies are needed to break bonds in $O_2$ and $O_3$.

Deduce the molecular geometry of $XeF_4$ and explain your answer.

Evaluate which of Formula A and Formula B is preferred using formal charge.

Distinguish formal charge from oxidation state in terms of the assumption made about bonding electrons.

Explain why the C$\equiv$N triple bond contains two $\pi$ bonds but only one $\sigma$ bond.

Suggest why a $\pi$ bond is usually weaker than a $\sigma$ bond.

Use physical evidence to discuss the bonding in benzene.

Discuss why benzene tends to undergo substitution reactions rather than addition reactions typical of alkenes.

Explain why the two C-O bonds in the ethanoate ion have the same length and why this length is intermediate between typical C-O and C=O bonds.