Chemistry 0620 · IGCSE · Formulae, functional groups and terminology

Formulae, functional groups and terminology — practice question

A diagram of the lactic acid structure is shown.
(a(i))[1]

On the displayed structure, circle the carboxylic acid functional group.

(a(ii))[1]

State the name of one further functional group present in lactic acid.

(b)[1]

State the molecular formula of lactic acid, including the numbers of carbon, hydrogen and oxygen atoms.

(c)[2]

Complete ethanol’s structure. Include every atom and every bond.

(d(i))[1]

What does the term volatility mean?

(d(ii))[1]

Which alcohol in the table has the greatest melting point?

(d(iii))[1]

Predict ethanol’s boiling point.

(d(iv))[2]

What state is propanol in at $120^\circ\text{C}$? Explain your answer.

(e(i))[2]

Complete the chemical equation for the incomplete combustion of methanol:\n\n$\text{CH}_3\text{OH} + \ldots\ldots\ldots\ldots \rightarrow \text{CO} + \ldots\ldots\text{H}_2\text{O}$

(e(ii))[2]

Calculate the relative molecular mass of methanol, $\text{CH}_3\text{OH}$. Show your working clearly. Use your Periodic Table to help.

Worked solution & mark scheme

This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: Draw a circle around the carboxylic acid group.

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