• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

2014 HSC Chemistry exam - Question 23 (1 Viewer)

apurba

Member
Joined
Nov 29, 2013
Messages
58
Gender
Male
HSC
2015
hsc chem 2014 q 23.PNGanswer to q23 hsc chem 2014.PNG

The answers say:

Answers could include: phosphates and hydrogen ions

My question was whether nitrate ions are also a valid answer since they also cause eutrophication.
 

dan964

what
Joined
Jun 3, 2014
Messages
3,479
Location
South of here
Gender
Male
HSC
2014
Uni Grad
2019
I will still learn "phosphates" as the best answer to the Q. I am sure "nitrates" would be technically accepted.
 

Mr_Kap

Well-Known Member
Joined
Mar 24, 2015
Messages
1,127
Gender
Male
HSC
2015
I will still learn "phosphates" as the best answer to the Q. I am sure "nitrates" would be technically accepted.
But why though?
What makes nitrates an inferior answer?
 

Ekman

Well-Known Member
Joined
Oct 23, 2014
Messages
1,615
Gender
Male
HSC
2015
But why though?
What makes nitrates an inferior answer?
Because when measuring the N:p ratio, in order to determine the amount of nutrients in a sample of water, phosphorus tends to be the growth limiting nutrient, hence we measure the N:p ratio according to the amount of phosphorus. The reason why phosphorus would be the better answer is because that is how eutrophication is determined, by the concentration of phosphorus.
 

Drsoccerball

Well-Known Member
Joined
May 28, 2014
Messages
3,650
Gender
Undisclosed
HSC
2015
Because when measuring the N:p ratio, in order to determine the amount of nutrients in a sample of water, phosphorus tends to be the growth limiting nutrient, hence we measure the N:p ratio according to the amount of phosphorus. The reason why phosphorus would be the better answer is because that is how eutrophication is determined, by the concentration of phosphorus.
You mean phosphates?
 

Ekman

Well-Known Member
Joined
Oct 23, 2014
Messages
1,615
Gender
Male
HSC
2015
You mean phosphates?
Actually, phosphorus causes the eutrophication. Of course the common way to dump phosphorus into waterways is when its in shampoos and detergents in the form of phosphates. So when you measure the N:p ratio, you don't measure the concentration of nitrates or phosphates, you measure the concentration of nitrogen and phosphorus.
 

Mr_Kap

Well-Known Member
Joined
Mar 24, 2015
Messages
1,127
Gender
Male
HSC
2015
Because when measuring the N:p ratio, in order to determine the amount of nutrients in a sample of water, phosphorus tends to be the growth limiting nutrient, hence we measure the N:p ratio according to the amount of phosphorus. The reason why phosphorus would be the better answer is because that is how eutrophication is determined, by the concentration of phosphorus.

So if I dumped a shit of nitrates into water and NO phosphorus, and we can see eutrophication, does that mean eutrophication cannot be determined quantitatively? lol. What even.
 
Last edited:

Ekman

Well-Known Member
Joined
Oct 23, 2014
Messages
1,615
Gender
Male
HSC
2015
So if I dumped a shit of nitrates into water and NO phosphorus, and we can see eutrophication, does that mean eutrophication cannot be determined quantitatively? lol. What even.
What you must understand is that the N[emoji14] ratio has limitations, because both nitrogen and phosphorus need to be present in the sample, so there are other ways of determining eutrophication quantitatively. Another common method is measuring BOD, which has no limitations. So does this answer your problem?
 

Mr_Kap

Well-Known Member
Joined
Mar 24, 2015
Messages
1,127
Gender
Male
HSC
2015
What you must understand is that the N[emoji14] ratio has limitations, because both nitrogen and phosphorus need to be present in the sample, so there are other ways of determining eutrophication quantitatively. Another common method is measuring BOD, which has no limitations. So does this answer your problem?
yeh i guess.
 

dan964

what
Joined
Jun 3, 2014
Messages
3,479
Location
South of here
Gender
Male
HSC
2014
Uni Grad
2019
What you must understand is that the N[emoji14] ratio has limitations, because both nitrogen and phosphorus need to be present in the sample, so there are other ways of determining eutrophication quantitatively. Another common method is measuring BOD, which has no limitations. So does this answer your problem?
haha emoji conversion.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top