At $200\,^{\circ}\text{C}$, aluminium chloride is present as Al$_2$Cl$_6$(g). Draw the structure of Al$_2$Cl$_6$(g), showing all coordinate (dative covalent) bonds in the molecule.
At $1000\,^{\circ}\text{C}$, aluminium chloride exists as AlCl$_3$(g). State the bond angle in AlCl$_3$(g).
Lithium hydride contains the ions Li$^+$ and H$^-$. State the electronic configuration of these two ions.
LiAlH$_4$ breaks down slowly to produce LiAl(s) and H$_2$(g): LiAlH$_4$(s) $\rightarrow$ LiAl(s) $+\,2$H$_2$(g). LiAl(s) shows metallic bonding. Describe metallic bonding.
LiAlH$_4$ cannot be used in aqueous solution because it reacts with water to form LiOH(aq), H$_2$(g) and a white precipitate that dissolves in excess sodium hydroxide. Identify the white precipitate.
Two students attempt to make 2-hydroxybutanoic acid in the laboratory. In reaction 1, both students oxidise butane-1,2-diol to produce P. State the reagents and conditions required for reaction 1.
Only one of the students successfully makes 2-hydroxybutanoic acid. Identify which of Q or R is 2-hydroxybutanoic acid and explain how reactions 2 and 3 differ.
A third student makes 2-hydroxybutanoic acid starting from propanal. In step 1, the student treats propanal with a mixture of NaCN and HCN. Draw the mechanism for the reaction of propanal with the mixture of NaCN and HCN to form S. Identify the ion that reacts with propanal. Draw the structure of the intermediate of the reaction. Include all charges, partial charges, lone pairs and curly arrows.
Complete the equation for the reaction in step 2, when S is heated under reflux with HCl(aq): C$_2$H$_5$CH(OH)CN $+$ ....................... $\rightarrow$ C$_2$H$_5$CH(OH)COOH $+$ .......................
Draw the mechanism for the reaction between propanal and the mixture of NaCN and HCN to form S. Identify the ion that reacts with propanal. Draw the structure of the intermediate of the reaction. Include all charges, partial charges, lone pairs and curly arrows.
Complete the equation for the reaction in step 2, when S is heated under reflux with HCl(aq). $\text{C}_2\text{H}_5\text{CH}(\text{OH})\text{CN} + \ldots \rightarrow \text{C}_2\text{H}_5\text{CH}(\text{OH})\text{COOH} + \ldots$
The infrared spectrum shown is for an organic compound. The compound could be S or 2-hydroxybutanoic acid. Deduce the identity of the compound. Give two reasons for your answer. In your answer, identify any relevant absorptions above $1500\,\text{cm}^{-1}$ in the spectrum and the bonds that correspond to these absorptions.