username3089818
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How to predict whether something has a higher melting or boiling point than another substance

The question is:
Predict whether CO2 will have a higher or lower boiling point than O2
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Cakecupcake
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CO2 is a larger molecule so stronger inter molecular forces and higher boiling and melting point
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(Original post by Cakecupcake)
CO2 is a larger molecule so stronger inter molecular forces and higher boiling and melting point
Thanks I knew this but the context question was in was really weird
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app_
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Higher, because CO2 contains more covalent bonds which require more energy to overcome

Also size of CO2 molecules are bigger than O2, so the intermolecular forces will be higher, and thus will require more energy to seperate = higher boiling point
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EdexcelAreIdiots
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(Original post by app_)
Higher, because CO2 contains more covalent bonds which require more energy to overcome

Also size of CO2 molecules are bigger than O2, so the intermolecular forces will be higher, and thus will require more energy to seperate = higher boiling point
Remember, (just so you don't get confused) covalent bonds don't break when covalent substances change state.
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(Original post by EdexcelAreIdiots)
Remember, (just so you don't get confused) covalent bonds don't break when covalent substances change state.
How about this

The chemical equation for the displacement of copper using iron is: CuSO4 + Fe → Cu + FeSO4 Calculate the minimum mass of iron needed to displace all of the copper from 50 cm3 of copper(II) sulfate solution. The concentration of the copper(II) sulfate solution is 80 g CuSO4 per dm3 . Relative atomic masses (Ar): O = 16; S = 32; Fe = 56; Cu = 63.5 Give your answer to 2 significant figures
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EdexcelAreIdiots
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(Original post by RJomana)
How about this

The chemical equation for the displacement of copper using iron is: CuSO4 + Fe → Cu + FeSO4 Calculate the minimum mass of iron needed to displace all of the copper from 50 cm3 of copper(II) sulfate solution. The concentration of the copper(II) sulfate solution is 80 g CuSO4 per dm3 . Relative atomic masses (Ar): O = 16; S = 32; Fe = 56; Cu = 63.5 Give your answer to 2 significant figures

50cm^3 = 0.05dm^3

Therefore we have 0.05*80 = 4g Copper sulfate

Moles Copper sulfate = 4/The Mr (can't be bothered to work it out)

1:1 ratio of copper sulfate to iron

Therefore 1 mole of iron displaces 1 mole of copper sulfate

Mass = moles x Mr

Mass Fe = (The moles of copper sulfate) x (Ar of Iron)
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username3089818
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[QUOTE=EdexcelAreIdiots;77668970]50cm^3 = 0.05dm^3



Thanks the numbers are the smae as markscheme so makes sense.how is ur revsiion going if u have exams
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EdexcelAreIdiots
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[QUOTE=RJomana;77669034]
(Original post by EdexcelAreIdiots)
50cm^3 = 0.05dm^3



Thanks the numbers are the smae as markscheme so makes sense.how is ur revsiion going if u have exams
I'm doing A-levels, just here to help you guys out. Probably should be revising though lol.
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[QUOTE=EdexcelAreIdiots;77669098]
(Original post by RJomana)

I'm doing A-levels, just here to help you guys out. Probably should be revising though lol.
OH god im so stressed I dont know anything .Do you mind if I keep asking questions
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EdexcelAreIdiots
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[QUOTE=RJomana;77669152]
(Original post by EdexcelAreIdiots)

OH god im so stressed I dont know anything .Do you mind if I keep asking questions
Sure, although I'd make sure that I'd go through past exams/ exams you did in class if I were you.
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[QUOTE=EdexcelAreIdiots;77669196]
(Original post by RJomana)

Sure, although I'd make sure that I'd go through past exams/ exams you did in class if I were you.
Yh im currently doing taht and teh questions that I search up for are taking from A-level old spec so its next level

nitric acid is a strong acid ethanoic acid is a weak acid.descrie a recation that could be used to show the differnce between a week and strong acid.Explain why the weak and strong acid give differnt results
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EdexcelAreIdiots
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[QUOTE=RJomana;77669336]
(Original post by EdexcelAreIdiots)

Yh im currently doing taht and teh questions that I search up for are taking from A-level old spec so its next level

nitric acid is a strong acid ethanoic acid is a weak acid.descrie a recation that could be used to show the differnce between a week and strong acid.Explain why the weak and strong acid give differnt results
I'm not sure if you need to know about the reactions to distinguish between them?

Strong acids are fully ionised - meaning all the molecules become ions when dissolved in water, in this case H3O+ NO3

Weak acids aren't - most of the molecules stay as molecules.
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[QUOTE=EdexcelAreIdiots;77669610][QUOTE=RJomana;77669336]

ts a 6 marker though
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[QUOTE=RJomana;77669642][QUOTE=EdexcelAreIdiots;77669610]
(Original post by RJomana)

ts a 6 marker though
A level?
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[QUOTE=EdexcelAreIdiots;77669670][QUOTE=RJomana;77669642]
(Original post by EdexcelAreIdiots)

A level?
No GCSE Combined Trilogy its come up on 2 practice papers so...
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joebloggs1787
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How do i know if something is ionic covalent simple or giant??
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[QUOTE=RJomana;77669698][QUOTE=EdexcelAreIdiots;77669670]
(Original post by RJomana)

No GCSE Combined Trilogy its come up on 2 practice papers so...
I suppose you could talk about electrical conductivity but other then that I'm not really sure?

Do you have a mark scheme?
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[QUOTE=EdexcelAreIdiots;77669768][QUOTE=RJomana;77669698]
(Original post by EdexcelAreIdiots)

I suppose you could talk about electrical conductivity but other then that I'm not really sure?

Do you have a mark scheme?
No teacher just gave practice questions
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