CSSA chemistry (4 Viewers)

[Midnight_Lotus]

Re: CSSA Chemistry 2011

Similar to what you got, cant remember exactly, i concluded that it was relatively safe because it was below the 650 ppm

 

[_deloso]

Re: CSSA Chemistry 2011

Apart from stuffing up a few question in industrial chem (solvay, experiment and sulfuric acid), I went beast on the paper. calculations were quite easy if you understand the concept. question: in the question where it says compare the octane with ethanol... How did you figure out the mole of octane in 1 litre? (having an argument with my friend bout it) Was the temp and pressure given in that question? cos if it was then moles were found using volume x gas constant.. and what was your answer for the distance travelled using 1 litre of ethanol?

 

[Midnight_Lotus]

Re: CSSA Chemistry 2011

Apart from stuffing up a few question in industrial chem (solvay, experiment and sulfuric acid), I went beast on the paper. calculations were quite easy if you understand the concept. question: in the question where it says compare the octane with ethanol... How did you figure out the mole of octane in 1 litre? (having an argument with my friend bout it) Was the temp and pressure given in that question? cos if it was then moles were found using volume x gas constant.. and what was your answer for the distance travelled using 1 litre of ethanol?

I originally tried using the gas constant for it but didnt seem right as i progressed through the questions, then i noticed it had like density 703g/L and 5000 kJ and there was different ones for ethanol so i used those. I got around 6.9km for the ethanol. There was no temp or pressure provided

 

[RANK 1]

Re: CSSA Chemistry 2011

got around 6.9 as well,

 

[_deloso]

Re: CSSA Chemistry 2011

i got like 354 ppm, pretty sure its wrong though, wat did u guys get

I found the mass of CO since it was 2% of 1kg. therefore, CO equals 20g. Then found the amount of moles 20/28 = 0.71, then found the volume.. 0.71 x 24.79 (gas constant) = 17.353.. and the room was 50m^3 therefore 50000L. and found the percentage of CO in 50000 (17.53 x 100 / 50 000 = 0.03506 %) and I think it was less than the v/v which was i think 0.06 in my memory

 

[_deloso]

Re: CSSA Chemistry 2011

I originally tried using the gas constant for it but didnt seem right as i progressed through the questions, then i noticed it had like density 703g/L and 5000 kJ and there was different ones for ethanol so i used those. I got around 6.9km for the ethanol. There was no temp or pressure provided

FAHhHHHHHH... full used the gas constant.... got 2.6 km. Stuffed that one up then!

 

[adz1098]

Re: CSSA Chemistry 2011

I found the mass of CO since it was 2% of 1kg. therefore, CO equals 20g. Then found the amount of moles 20/28 = 0.71, then found the volume.. 0.71 x 24.79 (gas constant) = 17.353.. and the room was 50m^3 therefore 50000L. and found the percentage of CO in 50000 (17.53 x 100 / 50 000 = 0.03506 %) and I think it was less than the v/v which was i think 0.06 in my memory

I did that exactly except, i though 1L equaled 1 M^3, i got like 35 %. ARGHHHHHH

Thhe calcs were pretty straaight forward overall, just stuffed up the dry cell question.

 

[Joy_2575]

Re: CSSA Chemistry 2011

Was it difficult guys? what were the 5 markers?
My school doesn't use CSSA for Chemistry - they decided to make their own papers! haha

 

[Blushii]

Re: CSSA Chemistry 2011

How many marks was the barbecue question? i tried to find the ppm but stuffed up marvelously lol!

I got ~6.9 for the car one aswell!

 

[Riproot]

I failed.
Also I got 354ppm but I didn't get the ethanol one. I couldn't remember anything and then stressed out a lot and fucked up the calculations.

 

[Midnight_Lotus]

Re: CSSA Chemistry 2011

How many marks was the barbecue question? i tried to find the ppm but stuffed up marvelously lol!

I got ~6.9 for the car one aswell!

was 3 or 4 marks i think

 

[husseinyahfoufi]

Re: CSSA Chemistry 2011

I found the mass of CO since it was 2% of 1kg. therefore, CO equals 20g. Then found the amount of moles 20/28 = 0.71, then found the volume.. 0.71 x 24.79 (gas constant) = 17.353.. and the room was 50m^3 therefore 50000L. and found the percentage of CO in 50000 (17.53 x 100 / 50 000 = 0.03506 %) and I think it was less than the v/v which was i think 0.06 in my memory

I did what you did I got 0.4 or something. But i didn't use moles. i went mg/L

 

[_deloso]

Re: CSSA Chemistry 2011

I did that exactly except, i though 1L equaled 1 M^3, i got like 35 %. ARGHHHHHH

Thhe calcs were pretty straaight forward overall, just stuffed up the dry cell question.

lol yup did that too.. just changed it to 50000 litres in my previous post cos i found out 1m^3 = 1000L. but yeah got 35% and said that it was way too much compared to 0.06%

 

[imZerroo]

Re: CSSA Chemistry 2011

lol yup did that too.. just changed it to 50000 litres in my previous post cos i found out 1m^3 = 1000L. but yeah got 35% and said that it was way too much compared to 0.06%

yup did the same thing. fk
come on though, we can't lose more than 1 mark, or 2 marks max?
did all the moles calculation right
and also i provided an assessment and said they will die a horrible death.
better get 3 marks for it or i chuck a pms.

 

[gaugau1]

Re: CSSA Chemistry 2011

Our teacher thought cssa was to easy this yr so she gave us the independent (apparently harder), but it was actually pretty good I aced the option

 

[jamesfirst]

Re: CSSA Chemistry 2011

Wtf at the octane and ethanol question............. I spent 30 min doing that and I think I did it wrong.

 

[Riproot]

It was fucking shit.

 

[jamesfirst]

The ethanol and octane question was hard..

 

[Dylanamali]

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?

 

[_deloso]

different to past cssa papers, needed to understand the concept behind it. hoping to get 85%+ hopefully