ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: Lesliel1 on March 10, 2011, 06:15:16 pm
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Hi,
I did a prac sac with potatoes where there are 6 test tubes with different salt concentrations- 0%, 0.5%, 1%, 5% and 10%. Then we had to find out the change in mass of the potatoes after we soaked them in the solutions for 30 mins.
then there was a question in the prac sac asking:
if the salt concentration of the potato cell was aprox. 0.9%, what would be the control?
i put in the one with distilled water (0%) and i dont know if it is right or wrong =(
could someone please tell me?
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the control would be the one closest to the intracellular concentration (in this case, the 1% solution).
Distilled water will still result in osmotic movement of water due to solute imbalance
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i put in the one with distilled water (0%) and i dont know if it is right or wrong =(
could someone please tell me?
You mentioned 6 test tubes, but only gave 5 concentrations. What was in the other test-tube? (although Russ is probably right)
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2%,
so im wrong? =( omggg =( but its still 0.9% not 1% lol :S
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2%,
so im wrong? =( omggg =( but its still 0.9% not 1% lol :S
1% is the closest. Go back to the definition of osmosis, and you'll see that the least mass lost/gained will be in this one. Of course the ideal control would have the same salt concentration as the potato. Its a tough question though.
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YOU HAD THE SAME PRAC AS ME :O
our solutions were 0%, 0.5%, 1%, 2.5%, 5% and 20% salt concentrated
theres a write up for this prac in heinemann workbook pg 37 btw ;)