General Thoughts: Chemistry (3 Viewers)

[muzeikchun852]

fuck, is it possible to get the seven marks only having used one page + a diagram

yeah they only expect you to write one page anyway.

 

[jung1239]

I can't remember learning why barium sulfate should go in soil when testing pH so i just bullshitted my way through.

I'm pretty sure because it's a white powder, it allows you to detect a colour change and therefore determine the pH.

 

[IamBread]

Yeah I got about that for the citric acid.

I usually find chem fairly hard, but I thought this test was quite easy... Odd.

 

[lolcakes52]

24b)ii 9.91g
iii)0.0689g
26) 0.967...i wrote acetic acid down instead of citric...anyone know how many mark's i'd loose? all 4? or would i get some for showing working?

Probs 1 or 2 if everything else was right, considering you only made one mistake i think its rediculous to penalise you.

 

[muzeikchun852]

For the arrhenius definition of acids and base I put that it was simpler than the bronsted-lowry and that it was still adequate in the majority of cases.

this. arrhenius's limitation on aqueous solution but still valid and correct.

 

[kleenextissues1]

For the arrhenius definition of acids and base I put that it was simpler than the bronsted-lowry and that it was still adequate in the majority of cases.

I wrote something about that it was still necessary to note the theory in the case of pH = -log[H+] ... amongst other things

 

[gunat61]

lol wth am i the only one here who found it hard ...

 

[jamesfirst]

concentrated sulphuric acid. None concentrated sulphuric acid won't fume.

will i lose a mark..........

 

[Nympha]

err. what's Domination & QED ?

He means he dominated the question. QED is "quod est demonstradum" which basically translates to thus it has been shown.

 

[khorne]

For the arrhenius definition of acids and base I put that it was simpler than the bronsted-lowry and that it was still adequate in the majority of cases.

This, Bronsty theory only helps explain non aqueous and amphoteric subtances.

24b)ii 9.91g
iii)0.0689g
26) 0.967...i wrote acetic acid down instead of citric...anyone know how many mark's i'd loose? all 4? or would i get some for showing working?

2-3 maybe...1 will be for correct answer, 1 for correct identification of reaction (i.e it ionises 3 times as citric)

I'm pretty sure because it's a white powder, it allows you to detect a colour change and therefore determine the pH.

Yeah, it's white.

 

[lolcakes52]

According to wikipedia:
Barium sulfate is also used during the procedure of the soil pH test. In this test it is used so that it precipitates out any particles (usually clay particles) that would otherwise 'cloud' solution preventing one from seeing the colour of the pH indicator i.e. the result of the test. It is also used in Episal salt, brake linings, anacoustic foams, powder coatings, and root canal filling.

 

[muzeikchun852]

24b)ii 9.91g
iii)0.0689g
26) 0.967...i wrote acetic acid down instead of citric...anyone know how many mark's i'd loose? all 4? or would i get some for showing working?

if i remember the question right, by saying acetic acid wont really matter unless your molar ratio is right.

 

[jamesfirst]

i wrote 2 pages for that 7 marker industrial chem one

-frasch process
-solvay process
-diaphragm process

same.

 

[lolcakes52]

He means he dominated the question. QED is "quod est demonstradum" which basically translates to thus it has been shown.

It is the equivalent to slapping the question and telling it to go home.

 

[silence--]

didn't really go as well as i would have liked

anyone reckon they can guess a state rank cutoff this year? i probs have no chance but... :L

 

[khorne]

According to wikipedia:
Barium sulfate is also used during the procedure of the soil pH test. In this test it is used so that it precipitates out any particles (usually clay particles) that would otherwise 'cloud' solution preventing one from seeing the colour of the pH indicator i.e. the result of the test. It is also used in Episal salt, brake linings, anacoustic foams, powder coatings, and root canal filling.

It's also a neutral salt, made from H2SO4 and BaOH(2)

 

[muzeikchun852]

According to wikipedia:
Barium sulfate is also used during the procedure of the soil pH test. In this test it is used so that it precipitates out any particles (usually clay particles) that would otherwise 'cloud' solution preventing one from seeing the colour of the pH indicator i.e. the result of the test. It is also used in Episal salt, brake linings, anacoustic foams, powder coatings, and root canal filling.

lol. i said it precipitates any fertiliser that might effect the pH of the soil. would get a mark for it ?

 

[khorne]

lol. i said it precipitates any fertiliser that might effect the pH of the soil. would get a mark for it ?

no.

 

[lolcakes52]

Don't worry about it, it was only one mark.

 

[mirakon]

no they didn't.


It was sulphuric acid.

boom boom shake da room i knew i guessed right!!!