Question

Write balanced equations for the following reactions: copper oxide and dilute hydrochloric acid.
Manganese (IV) oxide and concentrated hydrochloric acid.

(a) Name the experiment illustrated above.
(b) Which property of hydrogen chloride is demonstrated by this experiment?
(c) State the colour of the water that has entered the round-bottomed flask.

Answer 1

The reactions of both copper oxide and manganese dioxide with hydrochloric acid are given below:

CuO(s) + 2HCl(aq) → CuCl₂ (aq) + H₂O(l)
Copper Copper
oxide chloride

MnO₂ (s) + 4HCl(aq) → MnCl₂ (aq) + 2H₂O(l) + Cl₂(g)
Manganese Manganese
dioxide chloride
(black)

(a) The experiment shown in the diagram above is known as the fountain experiment.
(b) The fountain experiment shows that hydrogen chloride is highly soluble in water.
(c) The colour of water that enters the round bottomed flask will be red in colour.