CHEMISTRY 53. How was it??

[Anonymous']

What was the answer for the first question? I'm a bit confused

 

[jasters]

well the fist graph lines were a bit tricky

 

[ninesone]

it was so so.. hmm yeah qs 1.. whats the answer?

 

[jasters]

dont worry, it was only like 1 mark

 

[ninesone]

i thought it was supposed to be related for the qs 1 and total worth of 5 marks. but from markscheme, ecf is possible right..

 

[Nishii]

was your first question about lead?

 

[Anonymous']

was your first question about lead?

hmm.. no, the first question was asking about the effect on pressure when volume decreases.. I think your paper is not the same as ours.. heheh..

 

[monkeys12]

did you say that when volume decreases pressure also decreases?? and the graph was just a straight line graph?

 

[jasters]

did you say that when volume decreases pressure also decreases?? and the graph was just a straight line graph?

its a inverse proportion so no, pv=nrt , well the first question was strange

 

[Nishii]

hmm.. no, the first question was asking about the effect on pressure when volume decreases.. I think your paper is not the same as ours.. heheh..

yeah! thanks

 

[.Sam.]

Hmm, but if you think about it, they ask what is the effect of pressure when "Volume of (gas)" decreases [Not container]. So, the answer should be when volume of gas decreases in a 'fixed container', the pressure should decrease too because there's less molecules colliding the container walls. The P/V graph should be proportional.

 

[monkeys12]

Hmm, but if you think about it, they ask what is the effect of pressure when "Volume of (gas)" decreases [Not container]. So, the answer should be when volume of gas decreases in a 'fixed container', the pressure should decrease too because there's less molecules colliding the container walls. The P/V graph should be proportional.

that's what i thought as well! wonder what others have put..

 

[lilyanneth]

Hmm, but if you think about it, they ask what is the effect of pressure when "Volume of (gas)" decreases [Not container]. So, the answer should be when volume of gas decreases in a 'fixed container', the pressure should decrease too because there's less molecules colliding the container walls. The P/V graph should be proportional.

But to decrease the volume of gas shouldn't we decrease the volume of the container? I think you've confused it with decreasing the amount of gas in the container.. To say there's less molecules colliding with the container walls is wrong, because they mentioned that the mass of the gas is fixed. So technically, there are the same amount of molecules. But I could be wrong, I wasn't so sure of my answer myself :/

 

[.Sam.]

But to decrease the volume of gas shouldn't we decrease the volume of the container? I think you've confused it with decreasing the amount of gas in the container.. To say there's less molecules colliding with the container walls is wrong, because they mentioned that the mass of the gas is fixed. So technically, there are the same amount of molecules. But I could be wrong, I wasn't so sure of my answer myself :/

Decreasing the volume of gas "Without" decreasing the volume of container is possible (Eg. Turning the container partially vacuum)
I'm quite sure they said that the container is at fixed volume during compression and the number of gas molecules are to be varied.

 

[Henry930821]

Decreasing the volume of gas "Without" decreasing the volume of container is possible (Eg. Turning the container partially vacuum)
I'm quite sure they said that the container is at fixed volume during compression and the number of gas molecules are to be varied.

Question said fixed mass of gas. Mass wouldnt be constant anymore if the number of gas molecules is to be varied. Mass of gas = number of molecules x mass of each molecule