Complete the equation to show how excess sodium reacts with citric acid. Show the product as a skeletal structure.
Use the information in the table to work out the skeletal formula of $X$, $\text{C}_3\text{H}_6\text{O}_3$. Draw the skeletal formula of $X$ in the box. Label the chiral centre of compound $X$ with an asterisk ($^*$).
Explain why compound $X$ is oxidised by acidified $\text{Cr}_2\text{O}_7^{2-}$ whereas citric acid is not.
Compound $X$ belongs to one of a pair of stereoisomers. Stereoisomerism arises when a molecule has at least one of two key features. State the two key features that give rise to stereoisomerism.
A structural isomer of compound $X$ does not fizz when it is added to sodium. Explain what is meant by structural isomer.