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Solubility Equilibria Question (1 Viewer)

Carl10101

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Hello, does anyone know a good way to properly structure an answer to this question?

Info: Indigenous Australians detoxify the seeds of cycads, which contain the toxin cycasin. The seeds are crushed to expose the inner kernel and then soaked in water to leach out the water-soluble toxins.

Question: Describe the solubility equilibria of the toxins (4 Marks)

Thanks
 

jazz519

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I don't really remember this stuff that much but like just some things you should do in your answer:

- Describe the fruit or whatever you choose and how the toxins are removed
- Describe in terms of chemistry why the toxin is soluble while the other part of the fruit isn't (this is something you will probably have a better grasp on when you get to module 7 - as there is a large emphasis on things boiling point and solubility there)
- Give an equation if possible
 

Arrowshaft

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Hello, does anyone know a good way to properly structure an answer to this question?

Info: Indigenous Australians detoxify the seeds of cycads, which contain the toxin cycasin. The seeds are crushed to expose the inner kernel and then soaked in water to leach out the water-soluble toxins.

Question: Describe the solubility equilibria of the toxins (4 Marks)

Thanks
Just freshly graduated from chem, but still a bit cooked from the test aha, so I’ll answer it from the top of my head.

the seeds are ground in order to increase surface area to increase the solubility.

also remember the term dynamic equilibrium; this state is reached when the system is closed and no matter can leave or enter the system. Now, when the cycads are leached, this means that they are passed under running water usually from a creek. This means that the solution cannot get saturated to reach dynamic equilibrium - thus it cannot reach a state where the net dissolution is zero since water is continuously flushing out the toxins preventing it from saturating. Hence, when kept under running water for a while the toxins are made more soluble and eventually reach a concentration where the cycasin’s effect on the body is negligible (it doesn’t reach zero however). Also iirc (haven’t done this topic in a while lol) the cycad is pounded and roasted as well after?
 

Carl10101

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I don't really remember this stuff that much but like just some things you should do in your answer:

- Describe the fruit or whatever you choose and how the toxins are removed
- Describe in terms of chemistry why the toxin is soluble while the other part of the fruit isn't (this is something you will probably have a better grasp on when you get to module 7 - as there is a large emphasis on things boiling point and solubility there)
- Give an equation if possible
Just freshly graduated from chem, but still a bit cooked from the test aha, so I’ll answer it from the top of my head.

the seeds are ground in order to increase surface area to increase the solubility.

also remember the term dynamic equilibrium; this state is reached when the system is closed and no matter can leave or enter the system. Now, when the cycads are leached, this means that they are passed under running water usually from a creek. This means that the solution cannot get saturated to reach dynamic equilibrium - thus it cannot reach a state where the net dissolution is zero since water is continuously flushing out the toxins preventing it from saturating. Hence, when kept under running water for a while the toxins are made more soluble and eventually reach a concentration where the cycasin’s effect on the body is negligible (it doesn’t reach zero however). Also iirc (haven’t done this topic in a while lol) the cycad is pounded and roasted as well after?
Thanks this was very helpful. Yeah I think they are roasted after the initial process.

Thanks
 

Carl10101

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Update: I got a similar question in the multiple choice of my first assessment task (50 minute examination)

10. The people of the Tiwi islands in Northern Australia process yams (sweet potatoes) to make a food called bitter yam.

(picture)

Which of the following is an example of the use of solution equilibria to remove toxins from these yams?

(A) Leaching
(B) Fermentation
(C) Grinding to a powder
(D) Roasting

I put A which was correct
 

4u Boy

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I know this is supposed to be for questions but I have a dilemma and need some advice. So yesterday we did our first chem exam Mod5 and our teacher is known for making stupid hard tests like crazy hard - like nobody can finish the exam hard. Towards the end of the test, he goes around to collect equipment from the practical part of the exam and realizes that nobody has finished. BUT I did finish, he decides to add extra 10min to exam time (IS THAT ALLOWED?) So that can potentially be the difference of ranks. i . could have been a higher rank than someone whjo didnt finish.

If I tell the principal:
- it is most likely that he will know it is me
- he . will get kicked and we won't have a chem teacher for hsc for a period of time



But . on the other hand if I do tell:
- the exam will be redone
- and my mark and ranking would be fair


WHAT DO I DO????????
 

Carl10101

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I know this is supposed to be for questions but I have a dilemma and need some advice. So yesterday we did our first chem exam Mod5 and our teacher is known for making stupid hard tests like crazy hard - like nobody can finish the exam hard. Towards the end of the test, he goes around to collect equipment from the practical part of the exam and realizes that nobody has finished. BUT I did finish, he decides to add extra 10min to exam time (IS THAT ALLOWED?) So that can potentially be the difference of ranks. i . could have been a higher rank than someone whjo didnt finish.

If I tell the principal:
- it is most likely that he will know it is me
- he . will get kicked and we won't have a chem teacher for hsc for a period of time



But . on the other hand if I do tell:
- the exam will be redone
- and my mark and ranking would be fair


WHAT DO I DO????????
I am not sure if a teacher can be fired or kicked for simply adding 10 minutes to an exam's time limit
 

4u Boy

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I am not sure if a teacher can be fired or kicked for simply adding 10 minutes to an exam's time limit
yes he can, this is HSC rank . is super important and giving . anyone an advantage is unfair
 

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