CSSA chemistry (8 Viewers)

[Dylanamali]

Re: CSSA Chemistry 2011

There was a question about the pH of lemon juice -

I think the first part was just finding the pH and they already gave you the H+ conc. so it was just a matter of doing pH=-log(H+)

The next part was about dilution... I forgot the specifics of the question but I think my answer was like 400+mL, maybe 451mL or something

 

[Dylanamali]

Re: CSSA Chemistry 2011

Perfect!

was the Perfect! to my octane question?

 

[umz93]

Re: CSSA Chemistry 2011

Yes

 

[Riproot]

There was a question about the pH of lemon juice -
I think the first part was just finding the pH and they already gave you the H+ conc. so it was just a matter of doing pH=-log(H+)
The next part was about dilution... I forgot the specifics of the question but I think my answer was like 400+mL, maybe 451mL or something

It was lemonade in equilibrium with CO2 causing the pH and I got like 152mL :/
And then you had to say whether more CO2 would go into or out of solution/how equilibrium was effected.

 

[_deloso]

Re: CSSA Chemistry 2011

umz, how did you go? sounds like you went well...

I found it quite challenging..

What was your answer for the HCl being added to BaOH and the resulting pH of the solution.



Also what was the answer of what is the use of the Geiger counter.

And just a checking thing: in MCs there was a question comparing sulfuric acid and HCl - my answer was they have the same H+ and the same pH. Is that what you got?

that's what I meant by abstract questions where concepts must be understood and rote learning won't do you any good.
and yeah I got Same ph and concentration

 

[Midnight_Lotus]

Re: CSSA Chemistry 2011

It was lemonade in equilibrium with CO2 causing the pH and I got like 152mL :/
And then you had to say whether more CO2 would go into or out of solution/how equilibrium was effected.

It was asking if a base was added how the equilibrium would be affected

 

[Dylanamali]

Re: CSSA Chemistry 2011

It was lemonade in equilibrium with CO2 causing the pH and I got like 152mL :/
And then you had to say whether more CO2 would go into or out of solution/how equilibrium was effected.

The initial volume of the lemonade was 375mL if you wanted to dilute the concentration, you would expect a higher volume to dilute the conc.. therefore it MUST be greater than 375mL.

Oh yeah there was a question about what would happen if you added a base to the equilbrium and how it effects the solubility of carbon dioxide. It increase the solubility of CO2 producing more carbonic acid..

 

[Dylanamali]

Re: CSSA Chemistry 2011

that's what I meant by abstract questions where concepts must be understood and rote learning won't do you any good.
and yeah I got Same ph and concentration

Did you get the HCl + BaOH question? MC.

 

[umz93]

Re: CSSA Chemistry 2011

I dont remember the first part 0_o although i got the second part

 

[imZerroo]

Re: CSSA Chemistry 2011

Reading this thread, one question I go yay, and then next question I go, Oh Crap!
hopefully i get 50%.

 

[Dylanamali]

Re: CSSA Chemistry 2011

Reading this thread, one question I go yay, and then next question I go, Oh Crap!
hopefully i get 50%.

hahaha..

Did anyone get tricked by the Nuclear chemistry question... The one where you had to fill in what A and B were. I got Krypton-(forgot the weight) and Barium- (forgot the weight)

 

[umz93]

Re: CSSA Chemistry 2011

What weight?

 

[umz93]

Re: CSSA Chemistry 2011

I got the same
but didnt write any weight...

 

[Dylanamali]

Re: CSSA Chemistry 2011

What weight?

The weight was given.. the atomic mass.

 

[Dylanamali]

Re: CSSA Chemistry 2011

I got the same
but didnt write any weight...

It was Barium and Krypton but I don't think you can right just barium and krypton coz they are isotopes so you have to write the weight after each, e.g. Cobalt-60 .

 

[Riproot]

The initial volume of the lemonade was 375mL if you wanted to dilute the concentration, you would expect a higher volume to dilute the conc.. therefore it MUST be greater than 375mL.

Oh yeah there was a question about what would happen if you added a base to the equilbrium and how it effects the solubility of carbon dioxide. It increase the solubility of CO2 producing more carbonic acid..

IT ASKED HOW MUCH DISTILLED WATER WOULD BE ADDED YOU STUPID, MOTHER FUCKING PRICK!!! NOT THE FUCKING TOTAL VOLUME YOU FUCKING DUMB CUNT. DONT ACT LIKE A FUCKING SMART CUNT WHEN YOU DON'T READ THE QUESTION.

Yeah I got that for the CO2 one too.

 

[umz93]

Re: CSSA Chemistry 2011

Oh... well my teacher is lenient when it comes to those things hehehe
But thanks for telling me, hopefully wont bog me down in hsc

 

[Riproot]

It was Barium and Krypton but I don't think you can right just barium and krypton coz they are isotopes so you have to write the weight after each, e.g. Cobalt-60 .

Fucking hell, that's two marks I've gotten. Lol

 

[jamesfirst]

What were your answers to these MCs?

q4 was a calculation question, regarding ethylene being reacted with bromine. Do you remember what your answer was?
I'm preety sure you had to work out which one was not in excess then do molar ratio.s

Another question was what was the geiger counter used for? What is the answer....? There was no simple - detecting radiation

Also do you remember the question regarding the adding of HCl to BaOH, and the pH of the resultant solution. Do you remember your answer?

I did the answer that had UV light in it. Because if they were both colourless... it means that the cyclohexane have been affected by UV.

 

[Dylanamali]

Re: CSSA Chemistry 2011

IT ASKED HOW MUCH DISTILLED WATER WOULD BE ADDED YOU STUPID, MOTHER FUCKING PRICK!!! NOT THE FUCKING TOTAL VOLUME YOU FUCKING DUMB CUNT. DONT ACT LIKE A FUCKING SMART CUNT WHEN YOU DON'T READ THE QUESTION.

Yeah I got that for the CO2 one too.

haha fair enough, my mistake then =).
Ahh careless error then, just had to get my volume and minus from the origin. Did you use C1V1 = C2V2?