A-level Chemistry Revision Squad!

Original post by PlayerBB

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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I know how you feel :tongue:

See LOL!! I would of never guessed that figure, I was no where near it!! I'm not surprised though seeing as Diamond has all 4 of it's carbon covalently bonded to eachother leaving no free delocalised electrons/carbon atoms :wink:

Reply 21

Original post by FemaleBo55

I know how you feel :tongue:

LOL yeah exactly, maybe it has a higher one and we're both no where near it haha

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Reply 22

Mac.Doll

Finally! I can now get instant help from the chemistry Squad haha. :smile:

Thank you for making this!

Reply 23

Original post by PlayerBB

Lol you said it's nearest is 100

What I meant was, give your answer to nearest hundred, sorry for the confusion

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Original post by PlayerBB

Yeah I suck at guessing as well :tongue:

, maybe because of the giant lattice structure, it has a melting point around 1500 Celsius

Posted from TSR Mobile

nope

keep guessing

Reply 24

Original post by FemaleBo55

I know how you feel :tongue:

Nope

keep guessing...

Reply 25

Original post by Science_help

nope

keep guessing

Oh! that's okay and hmm okay 2500 C ?

Reply 26

Original post by PlayerBB

Oh! that's okay and hmm okay 2500 C ?

nope, but ill give you a clue.

Have you every seen/heard of liquid diamond ?

Reply 27

Original post by Science_help

nope, but ill give you a clue.

Have you every seen/heard of liquid diamond ?

No just heard of it but not actually seen it

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Reply 28

Ladymusiclover

I really need help with titration curves. I always mess up the end point and the vertical (it's always too long). I understand the principles/ For example I made the vertical from ph 5 to 11 with ethanoic acid and NaOH but the mark scheme said it had to be from ph 5.5 to 12 or something like that.

Reply 29

victoriawo19

I just got my official exam timetable for the summer and it seems that I'm entered for AS Chemistry for AQA and edexcel at the same time and date. Is that even allowed or do you guys think it's just a mistake? We have been doing the edexcel specification.

Reply 30

RMNDK

Original post by Ladymusiclover

That's quite cruel to be honest. I mean you understand the concept and you were pretty much spot on.

The pH values are just one of those things you need to learn. For instance, NaOH is a strong base and so will have a pH of 13-14.

pH values vary across exam boards. You might also be expected to recall pH values for specific compounds.
But you can try remember these steps.

What is being titrated? i.e. what's in the beaker. That's the starting pH. If it's a strong acid you're going to have a low pH of 1-3. If it's a weak acid, it'll be 3-6. If it's a strong base, it'll be 12-14. If it's a weak base, it'll be 8-11.

What is it being titrated against? i.e. what's in the burette. That's the thing that will change the pH. If it's a strong acid, the end will be 1-3. If it's a weak acid it'll be 3-6, and so on.

Draw the vertical portion at the equivalent point and about 1.5-2 pH off the end values. What I mean by this is say your end pH is 13 (e.g. your titrant is NaOH). Draw the vertical portion up to 11 or 11.5, maybe 12.

Combine the vertical portion with the two pH values by nice curves.

Reply 31

Original post by victoriawo19

You are not being taught the AQA syllabus for Chemistry then it is highly unlikely that you would need to do an exam on it. I think you should go to your examination officer/admin and talk about it to them see if they can withdraw you from the exam, or if it is a mistake they should give you a new timetable with the correct exam dates. What ever exam board you're doing you'll be given an exam paper based on it. It's one examboard per subject taught :smile:

Lol hope that helps :u:

Reply 32

Original post by Science_help

nope, but ill give you a clue.

Have you every seen/heard of liquid diamond ?

Original post by PlayerBB

LOL yeah exactly, maybe it has a higher one and we're both no where near it haha

Posted from TSR Mobile

Oh my lol if it's not 1500, is it around 3000-5000??? I can't imagine it to be any higher LOL -.-

Reply 33

Original post by FemaleBo55

Oh my lol if it's not 1500, is it around 3000-5000??? I can't imagine it to be any higher LOL -.-

You are close, yet really wrong.

@PlayerBB @FemaleBo55

the question was what temperature does diamond melt it....

answer is :

Spoiler

Reply 34

User1473160

Are you guys in year 12 or 13? I'm in year 12 :smile:

Reply 35

Original post by Science_help

You are close, yet really wrong.

@PlayerBB @FemaleBo55

the question was what temperature does diamond melt it....

answer is :

Spoiler

OMG! I feel really stupid not knowing that, but it was a really good question, yet a tricky one!

I am sure, it was hilarious for you seeing me and @FemaleBo55 trying to guess while on the other hand, it doesn't even melt haha :bricks:

Reply 36

Original post by Jade Li

Are you guys in year 12 or 13? I'm in year 12 :smile:

I'm in year 13

(edited 8 years ago)

Reply 37

samb1234

Original post by Science_help

You are close, yet really wrong.

@PlayerBB @FemaleBo55

the question was what temperature does diamond melt it....

answer is :

Spoiler

this isn't technically true. If you are talking about the kind of pressures we experience on earth than yes it will sublime, but at extremely high pressures it is possible to get liquid diamond, and there are a few predictions that liquid diamond may exist on other planets in our solar system. Also, although an interesting question this thread is probably better used for questions to which people can work out the answer to, rather than trivia or random guesses.

Reply 38