Draw a neat, labelled diagram to show that oxygen is released during photosynthesis.

Draw the standard HYDRILLA experiment: • a BEAKER containing water (with a little sodium bicarbonate to supply carbon dioxide) • a few sprigs of HYDRILLA placed with cut ends upward • a SHORT-STEMMED FUNNEL inverted over the plants • a TEST TUBE full of water inverted over the funnel stem, collecting the gas • BUBBLES of gas rising from the cut ends and gas collected at the top of the test tube • the whole apparatus in SUNLIGHT

Labels required: beaker, water, Hydrilla, funnel, test tube, gas collected (oxygen), sunlight.

THE TEST that proves the gas is oxygen, and it should be written beside your diagram: introduce a GLOWING SPLINT into the collected gas — it RELIGHTS, since oxygen supports combustion.

WHY EACH PART IS THERE, because examiners ask: HYDRILLA — an aquatic plant, so the gas it gives off can be collected as bubbles under water SODIUM BICARBONATE — supplies carbon dioxide, the raw material INVERTED FUNNEL AND TEST TUBE — channel and trap the gas so it does not escape SUNLIGHT — the essential condition; keep the apparatus in the dark and no bubbles appear, which is the control

Draw it large, in pencil, with labels outside the diagram on straight lines.