The Student Room Group

Hard buffer question

image.jpg
Attachment not found
Can anyone help with this hard OCR buffer question?
(edited 8 years ago)
Reply 1
Seriously need help please !!
Reply 2
whats the final pH that the mark scheme gives for part b?
My answer was 4.77
(edited 7 years ago)
Original post by AqsaMx
image.jpg
Attachment not found
Can anyone help with this hard OCR buffer question?


Could you give year/month/syllabus for this one please?
Original post by AqsaMx
image.jpg
Attachment not found
Can anyone help with this hard OCR buffer question?


more a stoichiometry question ...
Original post by ayvaak
whats the final pH that the mark scheme gives for part b?
My answer was 4.77


It can't have got more acidic!!!

The answer is 5.35
Reply 6
Original post by charco
It can't have got more acidic!!!

The answer is 5.35


Yep, could you explain please :smile:
Original post by AqsaMx
Yep, could you explain please :smile:


What do you not understand? You have written the correct equation and answer on your work that you posted.
Reply 8
Original post by TeachChemistry
What do you not understand? You have written the correct equation and answer on your work that you posted.


If the ratio between the metal, weak acid and salt is all 1 : 1 : 1 why then do we times the moles of magnesium by 2?
Original post by ayvaak
If the ratio between the metal, weak acid and salt is all 1 : 1 : 1 why then do we times the moles of magnesium by 2?


because 1 mole of magnesium reacts with 2 of acid
Reply 10
Original post by charco
because 1 mole of magnesium reacts with 2 of acid


Oh i see. Thanks
the persons working out is atrocious can someone please do some detailed working please ( write the new Ka equation and write steps to get the answer)
Original post by Sniperdon227
the persons working out is atrocious can someone please do some detailed working please ( write the new Ka equation and write steps to get the answer)


Why don't you post a lovely, tidy piece of work for us to look at?
Reply 13
Original post by Sniperdon227
the persons working out is atrocious can someone please do some detailed working please ( write the new Ka equation and write steps to get the answer)


Hahaaaaa, i wonder how lovely your working out is in exams
Original post by AqsaMx
Hahaaaaa, i wonder how lovely your working out is in exams


Just explain the q please
Reply 15
Screenshot_2016-05-24-15-18-52.pngI am currently stuck on question 5 of the photo. I was hoping someone could help. The answers C but i cant work out why. Thanks in advance.
Reply 16
I assume it's because a transition metal loses its first electron from a 4s^2 orbital and the second IE seems to be the biggest jump as there would only be one electron left in the 4s orbital so lot less energy to remove since the weakest attraction to nucleus since highest energy outer electron. I'm not sure though..

Quick Reply

Latest