Can someone please explain the trends down and across for first ionisations energys and boiling points etc im seriously struggling, also could you explain which deviate from the trend and how mg and Al differ, thanks!
Kk, what past papers should I do. Any common questions that usually come up? Also, how to prepare for section B, or is that just by hammering the past papers and you get a feel for them? Cheeeers
Kk, what past papers should I do. Any common questions that usually come up? Also, how to prepare for section B, or is that just by hammering the past papers and you get a feel for them? Cheeeers
Can someone please explain the trends down and across for first ionisations energys and boiling points etc im seriously struggling, also could you explain which deviate from the trend and how mg and Al differ, thanks!
First ionisation energies increase as you go across the periodic table because Electrons added to the same she'll Increased nuclear charge
First ionisation energies decrease down the groups because More e- so more shells Outer electrons further from nucleus so can easily be removed More shielding
Boiling points increase as u go down the groups due to the increase in van der waals (also applies to carbon chains - longer the chain - more van der waals - high boiling point )
Phosphorus and Sulphur deviate because sulfurs outer electrons repel eachother making it easier to remove an electron
Magnesium to Aluminum deviate because Mg outer electrons is is 3s subs hell where as Al is in a higher subshell 3p
Beryllium and Carbon deviate as beryllium outer shell electrons are in 2s subshell and carbons are in 2p subshell (a higher one)
First ionisation energies increase as you go across the periodic table because Electrons added to the same she'll Increased nuclear charge
First ionisation energies decrease down the groups because More e- so more shells Outer electrons further from nucleus so can easily be removed More shielding
Boiling points increase as u go down the groups due to the increase in van der waals (also applies to carbon chains - longer the chain - more van der waals - high boiling point )
Phosphorus and Sulphur deviate because sulfurs outer electrons repel eachother making it easier to remove an electron
Magnesium to Aluminum deviate because Mg outer electrons is is 3s subs hell where as Al is in a higher subshell 3p
Beryllium and Carbon deviate as beryllium outer shell electrons are in 2s subshell and carbons are in 2p subshell (a higher one)
Yoo thanks for taking the time to do this its helped me a lot ! Safe bro 😄
When you're testing for halides, I know you would normally add nitric acid and then silver nitrate but what would be the reason for adding the silver nitrate first and then the nitric acid? Any help would be appreciated- just can't seem to think why you would do it that way!
You have to add the Nitric Acid first as this removes any possible interfering ions. If you did this in reverse order a e.g. White precipitate may form but it might not be Silver Chloride like you expect it to be!
So the double bond repel the electrons in the Br-Br polarising it The Br-Br bond breaks and the Br closest to the double bond gives up its electrons to the other Br and sticks to the C atom The other C atom gets positively charged (carbocation) The Br- then bonds to the positive carbon It's just the same as you would do electrophilic addition with HBr
Can someone explain why dipole dipole is the answer
--> If this was NH4+, or CH4, there wouldn't be any dipoles because the molecule is surrounded by the same delta charge, so another molecule cannot be attracted to it as the like charges on the outside of each molecule will repel them away.
However, with CCl2F2, there is dipole-dipole formation. Why? Is it because of the polarity difference between C-F and C-Cl?
Can someone explain why dipole dipole is the answer
--> If this was NH4+, or CH4, there wouldn't be any dipoles because the molecule is surrounded by the same delta charge, so another molecule cannot be attracted to it as the like charges on the outside of each molecule will repel them away.
However, with CCl2F2, there is dipole-dipole formation. Why? Is it because of the polarity difference between C-F and C-Cl?
Fluorine is more electronegative so gets the delta negative forming a dipole so there is attraction between the opposite charges