New
New
Year 11
AQA
Foundation

The effect of sugar concentration on the mass of plant tissue: data analysis

I can interpret a graph showing the effect of sugar concentration on the mass of potato tissue, and explain the results.

New
New
Year 11
AQA
Foundation

The effect of sugar concentration on the mass of plant tissue: data analysis

I can interpret a graph showing the effect of sugar concentration on the mass of potato tissue, and explain the results.

Lesson details

Key learning points

  1. Plotting and interpretation of a graph showing the effect of sugar concentration on the mass of potato tissue.
  2. Increase in potato mass means water moved in by osmosis (because the sugar solution was more dilute outside).
  3. Decrease in potato mass means water moved out by osmosis (because the sugar solution was more concentrated outside).
  4. The concentration of sugar in the potato tissue can be determined from the point at which there was no change in mass.
  5. At this point the sugar concentration was equal inside and out, so there was no net movement of water.

Common misconception

Mistakes around calculating change in percentage mass are common, as are misunderstandings around why changes in mass occur.

The calculations for percentage mass are introduced and walked through with an 'I-do, we-do, you-do' model. There are plenty of calculations to practice on. Why mass changes occur is also covered in detail and with supporting diagrams.

Keywords

  • Osmosis - the net movement of water molecules through a selectively-permeable membrane from a dilute solution to a concentrated one

  • Net movement - the overall movement of particles

  • Random error - causes results to differ by different amounts due to a factor other than the independent variable (the factor we changed)

  • Concentration gradient - a difference in the concentration of particles from one area to another

It will probably take longer than expected to calculate the changes in mass, and plot the data on the graph, but give sufficient time for these tasks so students are confident with these skills which come up in various locations in the biology curriculum.
Teacher tip

Equipment

graph paper, rulers, pencils, calculators

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Match each variable to the correct example when investigating the effect of sugar solution concentration on potato chips.
An image in a quiz
Correct Answer:independent variable,concentration of sugar solution

concentration of sugar solution

Correct Answer:dependent variable,mass and length of potato chips

mass and length of potato chips

Correct Answer:control variable,temperature of the solutions

temperature of the solutions

Q2.
When investigating the effect of sugar solution concentration on potato chips, which piece of apparatus was used to control the temperature?
An image in a quiz
boiling tubes
timer
thermometer
Correct answer: water bath
Q3.
At which concentration did the potato chip decrease in mass?
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0.25 mol/dm$$^3$$
0.50 mol/dm$$^3$$
0.75 mol/dm$$^3$$
Correct answer: 1.00 mol/dm$$^3$$
Q4.
Which concentration caused the potato chips to lose water by osmosis?
An image in a quiz
0.25 mol/dm$$^3$$
0.50 mol/dm$$^3$$
0.75 mol/dm$$^3$$
Correct answer: 1.00 mol/dm$$^3$$
Q5.
Whose prediction is correct?
Lucas: Potato chips will gain mass in the most concentrated solutions.
Correct answer: Sam: Potato chips will lose mass in the most concentrated solutions.
Laura: The most concentrated solutions will have no effect on the potato chips.
Q6.
Water can move out of and into potato chips because the potato cells have a selectively- membrane.
Correct Answer: permeable

6 Questions

Q1.
Calculate the change in mass, in grams (g), for the potato chip in sugar solution at a concentration of 0.25 mol/dm$$^3$$.
An image in a quiz
Correct Answer: +0.07, +0.07 g, +0.07g
Q2.
Calculate the percentage change in mass (%) for the potato chip in sugar solution at a concentration of 0.25 mol/dm$$^3$$. Give your answer to 2 decimal places.
An image in a quiz
Correct Answer: +2.75, +2.75 %, +2.75%, 2.75%, 2.75
Q3.
Why is it necessary to calculate the percentage change in mass before comparing the effect of concentration on the potato chips?
Calculating the percentage is a more scientific measurement.
Not all the chips have the same final mass.
Correct answer: Not all the chips have the same initial mass.
The percentage is closer to the true value.
Q4.
Calculating the percentage change in mass helps to remove __________ error from the results.
calculation
percentage
Correct answer: random
systematic
Q5.
Match each direction of water movement to where it is shown on the graph.
An image in a quiz
Correct Answer:net movement into potato chip cells,when the line is above the x-axis

when the line is above the x-axis

Correct Answer:net movement out of potato chip cells,when the line is below the x-axis

when the line is below the x-axis

Correct Answer:no net movement,when the line crosses the x-axis

when the line crosses the x-axis

Q6.
Which point on the graph enables us to estimate the concentration of sugar inside the potato chip cells?
An image in a quiz
The point on the line where the change in mass was the most positive.
The point on the line where the change in mass was the most negative.
Correct answer: The point where the line crosses the x-axis.
The point where the line crosses the y-axis.