Chemistry 5070 · O Level · Carboxylic acids

Carboxylic acids — practice question

Coal is a blend of carbon compounds containing a small quantity of sulfur. The sample of coal is heated without air in the apparatus shown. The distillate is a mixture made up of a colourless liquid and tar.
(a)[2]

The colourless liquid includes ammonia, $\text{NH}_3$. Draw a ‘dot-and-cross’ diagram for ammonia, showing only the outer-shell electrons.

(b)[2]

Ethanoic acid is present in the tar. On warming with sulfuric acid, the ethanoic acid reacts with propanol to produce an ester. Name this ester and draw its structure, showing every atom and every bond.

(c)[2]

The tar also includes a compound with the composition shown below. Deduce the empirical formula of this compound.

(d(i))[2]

When coal burns, it releases an acidic gas that decolourises acidified aqueous potassium manganate(VII). This gas is a cause of acid rain. Identify this gas and describe how acid rain forms.

(d(ii))[1]

Give one harmful effect of acid rain on buildings.

(d(iii))[2]

Acid rain may negatively affect respiration. Write an equation that shows the process of respiration.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: three shared electron pairs between H and N

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI