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A-level Chemistry Revision Squad!

I was looking for a Chemistry Revision Thread but there were not any so I decided to make one :wink:

Feel free to ask questions regardless of your exam board (because chemistry is chemistry), and we'll all be happy to help!
(edited 7 years ago)

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Reply 1
I'll start it off: for the following ionic equation I've provided an explanation for it however, I'm not sure if it is right as I wrote it off top of my head:

S2O82-(aq)+ 2I-(aq) ---->2SO42-(aq) + I2(aq)

I wrote how as there is more moles of sulphate ions produced the colour of the solution will appear colourless even though the colour of Iodine is yellow-brown. Is this a true statement, lol?
I think even if the number of moles of SO4 are higher, the solution will appear yellow brown because of I2 even if pale yellow brown

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Reply 3
Original post by PlayerBB
I think even if the number of moles of SO4 are higher, the solution will appear yellow brown because of I2 even if pale yellow brown

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Why is that when the moles of SO4 is higher than I2??
Original post by PlayerBB
I think even if the number of moles of SO4 are higher, the solution will appear yellow brown because of I2 even if pale yellow brown

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Original post by FemaleBo55
I'll start it off: for the following ionic equation I've provided an explanation for it however, I'm not sure if it is right as I wrote it off top of my head:

S2O82-(aq)+ 2I-(aq) ---->2SO42-(aq) + I2(aq)

I wrote how as there is more moles of sulphate ions produced the colour of the solution will appear colourless even though the colour of Iodine is yellow-brown. Is this a true statement, lol?


Iodine is a grey-black solid...
Original post by FemaleBo55
Why is that when the moles of SO4 is higher than I2??


Look at the equation...You have a 2 in front of SO4. For every one mole of I2 there will be two of SO4.
Original post by High Stakes
Iodine is a grey-black solid...


Yh but in the equation, it says aq Iodine

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Original post by FemaleBo55
Why is that when the moles of SO4 is higher than I2??


Because the colour of aq SO4 ions is colourless however, the colour of aq Iodine is yellow brown, so even if the number of moles of Iodine produced is lower, it's colour will have an effect on the overall colour of the solution
Reply 8
Original post by PlayerBB
Because the colour of aq SO4 ions is colourless however, the colour of aq Iodine is yellow brown, so even if the number of moles of Iodine produced is lower, it's colour will have an effect on the overall colour of the solution


Oh okay LOL, I see where you're coming from! 😂 Thank youu!
Can anyone please explain to me what oxidising and reducing agents are and how they work in reactions. Much appreciated :smile:
Reply 10
Original post by DeadEnd_96
Can anyone please explain to me what oxidising and reducing agents are and how they work in reactions. Much appreciated :smile:


Oxidizing agent simply means that it oxidized another atom and was itself reduced, It has gained electrons by taking it from another atom.
Reducing agent means that it reduced another atom and was itself oxidized it has lost electrons by giving them to another atom.
Hope this helps
Lets see who gets this right.
No using google or textbook btw.

What temperature does diamond melt at ? nearest 100
Reply 12
Acidified Potassium Dichromate

lol
Original post by K3001N
Acidified Potassium Dichromate

lol


What?
Original post by Science_help
Lets see who gets this right.
No using google or textbook btw.

What temperature does diamond melt at ? nearest 100


98 ?

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you are a bit off :colonhash:
Original post by Science_help
Lets see who gets this right.
No using google or textbook btw.

What temperature does diamond melt at ? nearest 100


I know it has a higher melting point because of it's giant lattice lol, so I'm guessing around 800-900 Degrees Cecluis (LOL, I know it's probably wrong I suck at guessing!) :u:
Original post by Science_help
you are a bit off :colonhash:


Lol you said it's nearest is 100

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Original post by FemaleBo55
I know it has a higher melting point because of it's giant lattice lol, so I'm guessing around 800-900 Degrees Cecluis (LOL, I know it's probably wrong I suck at guessing!) :u:


Yeah I suck at guessing as well :tongue: , maybe because of the giant lattice structure, it has a melting point around 1500 Celsius

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goodluck

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