A student uses the apparatus shown in Fig. 1.1 to demonstrate that water is one of the products formed when a fuel burns. The gases made during combustion are drawn through the apparatus by means of a suction pump.
Fig. 1.1 contains labels: burning fuel, U-tube, ice, solid X, W, to suction pump.
The student then attempts to use the apparatus in Fig. 1.2 to pass the gases produced through acidified aqueous potassium manganate(VII).
There is a fault in the apparatus in Fig. 1.2, so the gases produced will not pass through the acidified aqueous potassium manganate(VII).
Fig. 1.2 contains labels: burning fuel, acidified aqueous potassium manganate(VII), Y, to suction pump.
(a)[1]
Identify the item of apparatus marked W in Fig. 1.1.
(b)[1]
When the fuel is burned, the steam formed moves into the U-tube. Suggest why the U-tube is surrounded by ice.
(c)[2]
Water makes solid X in the U-tube change colour. Name solid X and state the colour change observed. solid X ________. colour change from ________ to ________.
(d)[1]
Identify the item of apparatus marked Y in Fig. 1.2.
(e)[1]
On Fig. 1.2, draw a circle around the fault in the apparatus.
(f)[1]
Suggest why this colour change happens.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “a funnel” …