General thoughts: HSC chemistry 2015 (1 Viewer)

[Ekman]

what was the answer to reliability in MC? i said to test different pond sites from same place because my teacher said simply repeating experiment will improve measurability of reliability but not actually improve reliability

I said this as well. My teacher told me the same thing, because the aim of experiment is to measure the concentration of lead ions from the contamination site. Measuring from different ponds increase the reliability of your experiment, as well as measuring at different depths and different times of the day. Basically anything that increases your ability to take down more results.

 

[Catz]

Did we have to be specific about what equipement we used for measuring ozone concentration. I did ground equipement

 

[Crisium]

Did we have to be specific about what equipement we used for measuring ozone concentration. I did ground equipement

U.V spectrophotometer is used

But it can be in the ground-based form, weather balloon or TOMS

 

[Physicklad]

I personally thought this years exam was harder than last years, so hopefully marking isnt too harsh

srs? most questions were pretty generic

 

[diladial]

I said this as well. My teacher told me the same thing, because the aim of experiment is to measure the concentration of lead ions from the contamination site. Measuring from different ponds increase the reliability of your experiment, as well as measuring at different depths and different times of the day. Basically anything that increases your ability to take down more results.

was this one A???

 

[Bozzin8R]

I said this as well. My teacher told me the same thing, because the aim of experiment is to measure the concentration of lead ions from the contamination site. Measuring from different ponds increase the reliability of your experiment, as well as measuring at different depths and different times of the day. Basically anything that increases your ability to take down more results.

I said same pond. Simply because repeating the experiment of the same site several times increases reliability. Repeating from a different pond is a whole new set of data.

 

[Mr_Kap]

Yes, got burette!

I put burette but how is it burette???

its meant to be the volumetric pippete right???, which transfers the standard solution (OF KNOWN CONCENTRATION). I accidentally selected burette (realised it when i was putting my booklets together that i circled burette not volumetric pippete)


I am an idiot. I forgot to label my axis on the graph. Now that means i can only get 1 or 2 /4 .

 

[Crisium]

I said this as well. My teacher told me the same thing, because the aim of experiment is to measure the concentration of lead ions from the contamination site. Measuring from different ponds increase the reliability of your experiment, as well as measuring at different depths and different times of the day. Basically anything that increases your ability to take down more results.

But by checking from the same source multiple times you can determine whether there is a consistency in results + for it to be reliable it can be performed by other people but UNDER THE SAME CONDITIONS AND THE SAME LOCATION - Think about the measuring the value of G prac in physics; the value will vary on location and this kind of reflects that as well

Not sure if this makes sense though ...

 

[Catz]

What was the answer to question 20, pretty sure I got that wrong

 

[apurba]

fuck how many marks am i going to lose if i read the 4 mark calculation as "Acetic acid" instead of "citric acid" ?

 

[malcolm21]

I thought it was pipette? Dont you use the pipette to take a specific amt of primary standard out the volumetric flask into a conical flask, then drop by drop the burette which has the thing you dont know the concentration of??

 

[I97]

What was the answer to question 20, pretty sure I got that wrong

Think it was 0.38 kg

 

[Loudvicuna]

fuck how many marks am i going to lose if i read the 4 mark calculation as "Acetic acid" instead of "citric acid" ?

2

 

[Catz]

Think it was 0.38 kg

Was that D?

 

[apurba]

2

No, pretty sure I'll get 0

 

[SlimiJay]

for that question about what replaced CFCs, what did you guys put?

 

[apurba]

for that question about what replaced CFCs, what did you guys put?

fkn HFCs sleem come on

 

[Loudvicuna]

for that question about what replaced CFCs, what did you guys put?

the only one that was a HFC which was A i think, Post the paper for everyone here big fella?

 

[Loudvicuna]

fkn HFCs sleem come on

wat a dum kunt

 

[Crisium]

for that question about what replaced CFCs, what did you guys put?

HFC's since they don't contain chlorine or bromine (halons) and thus a zero ozone depleting potential

Funfact: They contribute to greenhouse gases though