Revision For Test - Osmosis Flashcards
Diffusion
1) is the spreading out of particles from an area of higher concentration to an area of lower concentration.
Where does it happen?
Happens in solution and gasses
E.g. perfume, or water and squash
How does diffusion happen?
1 spray of perfume in a room spreads so all the air is diffused so you can smell it from every bit of the room.
Osmosis
Is the movement of water molecules across a partially permeable membrane in from a less concentrated solution to more concentrated solution
Partially permeable membrane
Is just one with very small holes in it
Tiny molecules
(Like water) come past through it, but bigger molecules (E.G.sucrose) can’t
Water molecules
They can pass both ways through the membrane during osmosis
Water molecules (2)
Water molecules move from less concentrated solution (where they are lots of water molecules) to the more concentrated solution (where there are fewer water molecules)
Water molecules (3)
The water acts like it’s trying to even up the concentration either side of the membrane
You can observe the effects of sugar solution on plant tissue
Osmosis experiment
1) you’ve got a potato in the cylinder is that the same length and width.
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2). Get to beakers want to spill water and either with very concentrated sugar solution
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3) Measure the mass of the potato cylinders then put them in the beakers
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4) leave the potato cylinders for 24 hours in the beaker
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5) then take them out and try them with a paper towel
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6) Measure the masses again
