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• Flying grenade

  29 Oct 15, 23:49

  Rj and vjc jeanne tan and kim seng chan's green book

  'Principal quantum shell'

  https://www.dropbox.com/s/l5nf09oqsdg2v44/20151029_234652.jpg?dl=0

• UltimaOnline

  30 Oct 15, 00:01

  Originally posted by Flying grenade:

  Rj and vjc jeanne tan and kim seng chan's green book

  'Principal quantum shell'

  https://www.dropbox.com/s/l5nf09oqsdg2v44/20151029_234652.jpg?dl=0

  
  So you're gonna write that in your A levels? Suit yourself.
• Flying grenade

  30 Oct 15, 00:04

  Nope of course not lol. Im just sharing.

  I did my research.

  Im convinced that only *electron shell* is the right term. *principal quantum number* is the other term

• Flying grenade

  30 Oct 15, 02:29

  Whats the diff bet side product and by product?
• UltimaOnline

  30 Oct 15, 02:43

  Originally posted by Flying grenade:

  Whats the diff bet side product and by product?

  
  Go to my website by googling "BedokFunland JC", then look under my list of BedokFunland JC's A Level H2 Chemistry Questions. It's one of my questions, answers are provided therein.
• Flying grenade

  30 Oct 15, 12:26

  I cant find any questions with the title ' by product' or 'side product' in the list on your website
• Flying grenade

  30 Oct 15, 14:03

  Whats the diff between phase and states of matter? E.g gaseous phase / gaseous state
• Flying grenade

  30 Oct 15, 14:12

  http://infinity.usanethosting.com/Tuition/H2Chem_GiveThatManATehOIceLimau.jpg Sir for part 2 is the answer 0.229 kg (3sf)?
• UltimaOnline

  30 Oct 15, 15:00

  I typed the title using "byproduct" and "sideproduct". Look for it manually 1-by-1 lah, then you can see what other fun goody questions I have.
  
  For A level H2 Chem syllabus purposes, no diff.
• Flying grenade

  30 Oct 15, 15:06

  Do we need to know anything abt kstab?
• Flying grenade

  30 Oct 15, 15:14

  Walao sian wrong! !!!!!!!!!! Sir can help checkkkk )): Qn : For how much ice (kg) is it required to cool the water from 20 to 5°celSius ? Q1 = heat transferred to change temp of ice from -15 to 0°C (Endo) Q2 = heat transferred to change solid ice to liquid water at 0°c (endo) Q3 = heat transferred to change temp of water from 0 - 5°C (endo) Q4 = heat transferred to change liquid aqueous drink from 20-5°C (exo) at thermal eqm Q1+Q2+Q3+Q4 = 0
• Flying grenade

  30 Oct 15, 15:15

  Yea i looked 1 by 1 Hehe found it alr after 2nd try! !! Ur website so awesome!!!!! Ucdavis website credible hor?
• UltimaOnline

  30 Oct 15, 15:16

  Originally posted by Flying grenade:

  Walao sian wrong! !!!!!!!!!!
  Sir can help checkkkk )):

  Qn : For how much ice (kg) is it required to cool the water from 20 to 5°celSius ?

  Q1 = heat transferred to change temp of ice from -15 to 0°C (Endo)
  Q2 = heat transferred to change solid ice to liquid water at 0°c (endo)
  Q3 = heat transferred to change temp of water from 0 – 5°C (endo)
  Q4 = heat transferred to change liquid aqueous drink from 20-5°C (exo)

  at thermal eqm Q1+Q2+Q3+Q4 = 0

  
  Ooops pai sei, my bad. Your answer is correct, I didn't read properly. Well done Lol!
• UltimaOnline

  30 Oct 15, 15:20

  Originally posted by Flying grenade:

  Yea i looked 1 by 1
  Hehe found it alr after 2nd try! !!

  Ur website so awesome!!!!!
  Ucdavis website credible hor?

  
  Yeah, but of course, in my question using their image (with acknowledgements), we're talking literally hydrolysis (ie. using water as a reagent). In the H2 syllabus, becoz time is money, to save time we use a stronger nucleophile and base, NaOH(aq) and NaOH(ethanol), and thus the by-product will be be NaBr instead of HBr. But you get the idea.
• UltimaOnline

  30 Oct 15, 15:21

  Originally posted by Flying grenade:

  Do we need to know anything abt kstab?

  
  Good to know (afterall, it combines equilibria and complex ions in the H2 syllabus), Prelim papers often ask on it, and Cambridge can use it in a data-based qn (ie. they tell u what's Kstab, then ask u to apply).
• Flying grenade

  1 Nov 15, 03:15

  Rj book ionic equilibria page 285
  
  Exercise: analysing a mixture of NaHCO3 and NaOH
  
  Is the conc NaOH given by the answer 0.430mol/dm3 correct?
  
  I tried both different method twice,
  
  I got [NaOH] 0.130mol/dm3
  
  Also, actually, i dont really understand the examples.
  
  Why vol of hcl required to react with NaOH intially present in the mixture, can be equated to Vhcl used during first end point minus Vhcl used in 2nd end pt??
  
  So like 1st end pt only have oh-??then after all oh- are neutralised, then suddenly have HCO3- ion come out from the dissociation of NaHCO3??
  
  Shouldn't the dissociation be concurrent?
  
  Is it becos strong base suppress the dissociation of WB NAHCO3?
  
  If ^ that is the case, then why the book indicated 'at the first end pt, total amount of hcl reacted with both Na2CO3 and NaOH = the vol hcl used in first end pt??? Im confused and i dun uds dun get it ...
  
  Can help improve my phrasing or how should i ask my question in the proper manner also
  
  
• Flying grenade

  1 Nov 15, 03:23

  And i have no idea why when i post posts in this forum, sometimes some portions of the words become small or big.. Sorry for the weird word warping above^ I have no idea of how rectify or fix it
• Flying grenade

  1 Nov 15, 03:30

  Zzzzzzzzzzzzzzzzzzzz. They gave explanation on the following page 287. Zzzzzzzz I wasted alot of time contemplating and thinking about it. =_= You could still kindly input anything if you would like I appreciate and thank you so much ultima (:
• UltimaOnline

  1 Nov 15, 04:02

  25 cm3 of NaHCO3 and NaOH titrated against 0.5M HCl. 21.5cm3 and 15cm3 of HCl required to reach 1st and 2nd equivalence points respectively. Find the molarities of NaHCO3 and NaOH.
  
  Solution :
  
  Molarity of NaOH = moles of HCl which neutralized NaOH / 25cm3 volume = (0.5(21.5/1000)) / (25/1000) = 4.3x10^-1 M
  
  Molarity of NaHCO3 = moles of HCl which neutralized NaHCO3 / 25cm3 volume = (0.5(15/1000)) / (25/1000) = 3x10^-1 M
• Flying grenade

  3 Nov 15, 17:57

  Whats the difference between L (levo) and D (dextro) , And sinister and dexter isomers???? And also R and S isomers??
• UltimaOnline

  3 Nov 15, 19:34

  Originally posted by Flying grenade:

  Whats the difference between L (levo) and D (dextro) , And sinister and dexter isomers???? And also R and S isomers??

  
  To answer your question, read :
  https://en.wikipedia.org/wiki/Chirality_(chemistry)#Naming_conventions
  
  For H2 Chemistry, if asked to name the enantiomers, Cambridge will accept either (+)/(-) or d/l labelling based on optical activity, or the R/S labelling based on the Cahn–Ingold–Prelog priority rules (which are also used for E/Z labelling system for alkenes, which is more versatile than the limited cis/trans system, and is also accepted by Cambridge for H2 Chemistry) though the R/S and E/Z labels are not compulsory for H2 Chemistry as it's not within syllabus, and only required for H3 Chemistry. The D/L labelling is used in biochemistry (H2/H3 Biology).
• Flying grenade

  3 Nov 15, 20:11

  There's Cis trans (+)/(-) d/l D/L Rectus sinister E Z rules Which one is for geometric isomerism and optical isomerism? Which one rotates clocks and anti clockwise? Only manage to find for R and S , which is clockwise for rectus and anticlockwise for sinister
• UltimaOnline

  3 Nov 15, 22:00

  Originally posted by Flying grenade:

  There’s
  Cis trans
  (+)/(-)
  d/l
  D/L
  Rectus sinister
  E Z rules

  Which one is for geometric isomerism and optical isomerism?

  Which one rotates clocks and anti clockwise?

  Only manage to find for R and S , which is clockwise for rectus and anticlockwise for sinister

  
  No seriously, all the info is out there. Not gonna spoonfeed you anymore here (besides, most of this is optional stuff, beyond the H2 syllabus essentials). Go read 5 diff websites (including Jim Clark's, Khan's Academy, etc).
• Flying grenade

  3 Nov 15, 23:33

  2010 p3 qn 1d Sir ultima can help check my drawings For cpd A, the cl is substituted at that position is it because it is most stable there because attached to 3 mildly electron donating C group ah? Markovnikov's rule ah? For D, im asking this as an extension When the Br is being eliminated, are there 2 other by-product as drawn? https://www.dropbox.com/s/lo7wynbasjbmo7k/20151103_233025.jpg?dl=0
• Flying grenade

  3 Nov 15, 23:44

  Wait for ^ should *side* product be the proper term to use? Haha