How Distilled Water Affect The Rate Of Osmosis

The hypothesis made prior to the experiment was not correct - the distilled water did result in the most weight gain (g); however, the 5% salt concentration did not result in the least weight gain (g). Table 1 clearly highlights that the 3% salt concentration resulted in the least weight gain (g). The distilled water resulted in the most weight gain (g) because the solution is hypotonic – a hypotonic solution results in the water diffusing into the cell because the molecules of the substance are moving from an area of higher concentration (outside of the cell) to an area of lower concentration (inside the cell) (Hammel & Schelegel 2005). Therefore, the water was moving into the cell, causing the potato cell to increase in size. The potato appeared to be quite turgid and swollen through observation. The 3% salt solution resulted in the least weight gain (g) because the solution is hypertonic – a hypertonic solution results in the water diffusing out of the cell because the molecules of the substance are moving from an area of lower concentration (inside the cell) to an
It could be hypothesised that the cell had to draw in extra salt following the substantial weight loss from the 3% salt solution. Thus, the cell immersed in the 5% salt solution gained weight following the 3% salt solution. This could be examined further in another study regarding osmosis and weight gain in plant cells. In Figure 2, it highlights that the average weight (g) from the individual data had a higher ‘before weight (g)’, compared to the class data, which had a lower ‘before weight (g)’. It is assumed that this is due to the original weight (g) of the potato – the potato was either heavier in comparison to the other potatoes in the class or there was an error in preparation and measurement (i.e. the potato was not blotted