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Variables in an osmosis investigation
A student investigated the concentration of salt in solution Z. The student used a method involving osmosis and tubing made of partially permeable membrane.
This is the method used.
- Cut six pieces of tubing to the same length.
- Tie one end of each piece of tubing.
- Put the same volume of solution Z into each piece of tubing.
- Tie the other end of each piece of tubing to form a sealed tube.
- Record the mass of each tube.
- Place each tube into a different concentration of salt solution.
- After 2 hours, remove each tube from the salt solutions.
- Record the mass of each tube.
What was the independent variable for the investigation? Tick one box.
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Marking points
- 1 Selects 'Concentration of salt solution'.
Why this answer loses marks
The measured change is the independent variable.
The measured change is the outcome; the independent variable is the condition deliberately changed between tubes.