A student investigated the effect of different concentrations of sugar solution on pieces of potato - AQA - GCSE Biology Combined Science - Question 1 - 2020 - Paper 1
Question 1
A student investigated the effect of different concentrations of sugar solution on pieces of potato.
This is the method used.
1. Cut five pieces of potato.
2. Reco... show full transcript
Worked Solution & Example Answer:A student investigated the effect of different concentrations of sugar solution on pieces of potato - AQA - GCSE Biology Combined Science - Question 1 - 2020 - Paper 1
Step 1
What is the independent variable?
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Answer
The independent variable is the concentration of the sugar solution.
Step 2
Explain why the potato in 0.0 mol/dm² sugar solution increased in mass.
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Answer
The potato gained water (water moves) by osmosis. This occurs because the concentration of water outside the potato is greater than that inside the potato cells. As a result, the water moves from an area of high concentration (the surrounding solution) to an area of low concentration (the inside of the potato cells) until equilibrium is reached.
Step 3
Complete Figure 1.
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Answer
All points from Table 1 should be plotted correctly on the graph provided. The line of best fit should then be drawn, connecting the plotted points without needing to extend beyond them.
Step 4
Determine the concentration of sugar solution inside the potato cells.
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Answer
The concentration of sugar solution inside the potato cells is approximately 0.3 mol/dm², as inferred from the graph where the mass change is zero.
Step 5
Calculate the percentage change in mass for the potato in 0.2 mol/dm² sugar solution.
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Answer
Using the data from Table 1:
Change in mass = 0.25 grams
Starting mass = 7.96 grams
Percentage change in mass can be calculated as follows:
percentage change in mass=7.960.25×100=3.14 (to 3 significant figures)