The Mega Alevel Chemistry help thread.... 2013!

You guys aren't quoting properly - make sure you check the quote tags are done correctly.

Reply 23

Can anyone help me me in Gas Lawplease

Reply 24

b4tman

7

Original post by otrivine

Can anyone help me me in Gas Lawplease

Oh god! Boyles law pressure ∝ 1/volume at fixed temperature for fixed mass of gas

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Reply 25

Original post by b4tman

Oh god! Boyles law pressure ∝ 1/volume at fixed temperature for fixed mass of gas

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Not gas laws , this, I just dont get why this is in chemstry? it should be physics

Reply 26

OP

Original post by Natalie21

OCR A says above +0.3V is feasible. +0.3V to -0.3V is in equlibrium. And below -0.3V is not feasible under standard conditions.

hmmm...can you look at my question on #16? :smile:

Reply 27

A set of car tyres, each of volume 21.0 dm3, were inflated till the pressure gauge read 28.5 lb in-2 . During a journey, the temperature of the tyres increased from 15 °C to 42 °C and their volume increased to 21.6 dm3. What would the pressure gauge have read then? (The pressure of air in the tyre was the sum of the gauge pressure and atmospheric pressure, which may be taken as 14.7 lb in-2 )

I am stuck on this i get 30.3 and mark scheme gets 31.2

Reply 28

OP

Original post by otrivine

A set of car tyres, each of volume 21.0 dm3, were inflated till the pressure gauge read 28.5 lb in-2 . During a journey, the temperature of the tyres increased from 15 °C to 42 °C and their volume increased to 21.6 dm3. What would the pressure gauge have read then? (The pressure of air in the tyre was the sum of the gauge pressure and atmospheric pressure, which may be taken as 14.7 lb in-2 )

I am stuck on this i get 30.3 and mark scheme gets 31.2

Why so big? :argh:

Reply 29

Original post by Future_Dr

Why so big? :argh:

sorry I think my computer does automatically! was trying to draw peoples attention ? can you help me on this future_dr :smile:

Reply 30

OP

Original post by otrivine

sorry I think my computer does automatically! was trying to draw peoples attention ? can you help me on this future_dr :smile:

No idea on physcial chemistry.. We do this in in our last unit. :redface:

Reply 31

Original post by Future_Dr

No idea on physcial chemistry.. We do this in in our last unit. :redface:

Yes

how have u been :smile:

Reply 32

b4tman

7

Original post by otrivine

A set of car tyres, each of volume 21.0 dm3, were inflated till the pressure gauge read 28.5 lb in-2 . During a journey, the temperature of the tyres increased from 15 °C to 42 °C and their volume increased to 21.6 dm3. What would the pressure gauge have read then? (The pressure of air in the tyre was the sum of the gauge pressure and atmospheric pressure, which may be taken as 14.7 lb in-2 )

I am stuck on this i get 30.3 and mark scheme gets 31.2

I got 30.3 at first, but I realised you have to add the atmospheric pressure to the pressure gauge reading of 28.5 and use that as the pressure initially, then minus it again at the end

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Reply 33

OP

[QUOTE="Mrkingpenguin;41559354"]

Original post by Future_Dr

Please for the love of God change the title,

Yeah.. I sent a report to the mod.. still waiting. I just made the 'G' in Gaint in lower case and also H in help. :colondollar:

Reply 34