You will need to use apparatus appropriately to measure out the volumes of your solutions and record your measurements
To find the percentage change in mass, the change in mass must be divided by the initial mass and then multiplied by 100
A positive percentage change in mass indicates that the potato has gained water by osmosis
Light micrographs of normal red onion cells alongside those that have plasmolysed (artistic impression). The cells on the left are epidermal cells that have been immersed in distilled water, whilst the cells on the right are epidermal cells that have been immersed in 1.0 mol dm⁻³ sucrose solution.
Questions involving experiments investigating osmolarity and osmosis are common and you should be able to use your knowledge of osmosis to explain the results obtained. Don’t worry if it is an experiment you haven’t done – simply figure out where the higher concentration of water molecules is – this is the solution with the lower osmolarity – and explain which way the molecules move due to the differences in osmolarity.