detergent (1 Viewer)

[crammy90]

any1 know an quantitative way to test for detergent?
would it be adding an acid or somthing?
and when we titrate a sample with EDTA to determine CaCO3 (ppm) for hardness, i thought we didnt use weak acids as its hard to determine their end point...
would any1 like to shed some summary info on EDTA because wikipedia is a bit overwhelming and i dont know how much we need to know about it

and could a qualitative test just be a quantitative test where u dont make measurements i.e. testing for heavy metals. We could add NaS and calculate mass of precipitates etc, or we could make it qualitative and just add the NaS and conclude there are heavy metals?

is BOD an indication of eutrophication?

 

[syriangabsta]

any1 know an quantitative way to test for detergent?
would it be adding an acid or somthing?
and when we titrate a sample with EDTA to determine CaCO3 (ppm) for hardness, i thought we didnt use weak acids as its hard to determine their end point...
would any1 like to shed some summary info on EDTA because wikipedia is a bit overwhelming and i dont know how much we need to know about it

and could a qualitative test just be a quantitative test where u dont make measurements i.e. testing for heavy metals. We could add NaS and calculate mass of precipitates etc, or we could make it qualitative and just add the NaS and conclude there are heavy metals?

is BOD an indication of eutrophication?

test for detergent? what do you mean, if a solution contains detergent? lol?

ill skip the hard water part, whats EDTA btw?

qualitative is just like a yes or no thing. whereas quantitative is calculating measurements etc,

now, for your example you've given, you cant just "conclude" that there will be heavy metals, unless you can see it, ie prove it. so like if a certian reaction occurs, you can conclude that heavy metals are present, and this would be qualitative.

erm, about the BOD, well....eutrophication is an increase in nutrients, which leads to algal boom. these algal then use up the DO , and you get an increase in BOD...

so, you could say that an increase in BOD can be caused by eutrophication..although theres other ways BOD can occur isnt there? :S yer i need help too

 

[danz90]

test for detergent? what do you mean, if a solution contains detergent? lol?

ill skip the hard water part, whats EDTA btw?

qualitative is just like a yes or no thing. whereas quantitative is calculating measurements etc,

now, for your example you've given, you cant just "conclude" that there will be heavy metals, unless you can see it, ie prove it. so like if a certian reaction occurs, you can conclude that heavy metals are present, and this would be qualitative.

erm, about the BOD, well....eutrophication is an increase in nutrients, which leads to algal boom. these algal then use up the DO , and you get an increase in BOD...

so, you could say that an increase in BOD can be caused by eutrophication..although theres other ways BOD can occur isnt there? :S yer i need help too

EDTA I believe is a chelating agent which basically binds to heavy metals.
It is not actually a full requirement of syllabus.. but has been given before in a HSC paper.

With eutrophication.. I always thought that it was the increase in algal blooms that blocks sunlight, preventing photosynthesis (which produces oxygen) of aquatic plants.. hence reducing DO. Therefore, since there are anaerobic conditions... anaerobic bacteria break down organic matter, releasing noxious and toxic gases such as ammonia, hydrogen sulfide and methane.. which ultimately degrade the waterway severely.

 

[crammy90]

alrite sweet,
yeh your both got eutrophication down pat

[SIZE=-1]

Chelating agents are used in facial and body washes, body scrubs and shampoos to deactivate hard calcium and magnesium minerals which can form dulling, film-forming lime soap deposits when hard water comes in contact with the pure soaps.
www.intelcosmet.com/content/view/48/25/lang,FR/

[/SIZE]So from this a chelating agent would also be used in water treatment to remove hardness yeh? or is it added just to detergents n stuff...If so in water treatment any1 know what step? and also:
[SIZE=-1]

An organic (hydrogen and carbon-containing) compound that binds to charged metallic atoms (ions) to increase absorption.[/SIZE]

does this mean it could be used in AAS. This definition is referring to absorption in the body but yeh...just puttin it out there ahah


and for the qualitative and quantitative i get what you mean. I couldnt just put in the S and say "a precipitate formed, all heavy metal sulphides are insoluble, thus there are heavy metals present"...how would u qualitatively identify heavy metals?

 

[syriangabsta]

alrite sweet,
yeh your both got eutrophication down pat

[SIZE=-1]
[/SIZE]So from this a chelating agent would also be used in water treatment to remove hardness yeh? or is it added just to detergents n stuff...If so in water treatment any1 know what step? and also:
[size=-1]
does this mean it could be used in AAS. This definition is referring to absorption in the body but yeh...just puttin it out there ahah


and for the qualitative and quantitative i get what you mean. I couldnt just put in the S and say "a precipitate formed, all heavy metal sulphides are insoluble, thus there are heavy metals present"...how would u qualitatively identify heavy metals?

if its a cation (heavy metal) i suppose you can use AAS..

about the qualitatively...If lets say X + Y --> white precipitate, and a white precipitate indicates a certian heavy metal...Then its a qualitative test if u didnt measure the amount of X and Y added....

so, you can say that....The following heavy metal is present in this solution as a white pppt formed. <that would be qualitative

i dont know if i answered your q lol

 

[brenton1987]

and when we titrate a sample with EDTA to determine CaCO3 (ppm) for hardness, i thought we didnt use weak acids as its hard to determine their end point...
would any1 like to shed some summary info on EDTA because wikipedia is a bit overwhelming and i dont know how much we need to know about it

An EDTA titration is not an acid base titration rather it is a complexiometric titration. That is the complexation of a metal ion to a large organic molecule. In this case the large molecule is the hexadentate chelator EDTA.
When titrating calcium with EDTA there is an indicator present. At v_EDTA = 0 the calcium is complexed to an indicator such as eriochrome black t to give a red coloured solution. As EDTA is added the calcium preferentially complexes with EDTA as opposed to ECBT and the red colour reduces intensity. At the end point there is now a slight excess of EDTA so all the calcium is complexed to it. The now uncomplexed free ECBT changes to blue in its uncomplexed state. Concentration calculations follow as with an acid base titration.

To compare it to acid base: The calcium is the proton, EDTA is the base and eriochrome black is the indicator. The protonated indicator is red in color and when completely unprotonated it becomes blue. Unprotonated and protonated base have no effect on colour.