2018 H2 Chemistry JC students post your questions here
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BedokFunland JC's Social Responsibility to Support Students on Financial Assistance :
If you cannot afford Private Tuition, you can post your Chemistry questions here on SgForums, and I will help you out with all your A Level & O Level Chemistry questions free-of-charge.
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Greets to 2018 JC1 Students!
Why JC1 students should join BedokFunland JC as soon as you confirm your JAE posting to a JC :
Unlike other Tuition Centers which only re-teach what your school has already taught, I will teach you ahead of your school, thus giving you a valuable advantage over the rest of your peers. Having already learnt from me the topic your school is about to teach, you will get to enjoy your school's lectures and tutorials because you already understand the topic, while you see the rest of your peers become confused and frustrated during your school's lectures and tutorials.
"Should I try studying H2 Chemistry on my own 1st, and wait until the Mid Year Exams to see whether I need Tuition or not?"
While that is the common thinking of many JC1 students, the problem is, if you fail your Mid Year Exams, for many students, it would already be too late to catch up in time to pass your Promotional Exams, bearing in mind you'll also be struggling to catch up with multiple subjects (both H2 and H1) all at the same time. Prevention is Better than Cure.
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This thread is open to all 2018 Singapore JC students studying H2 Chemistry, whether you're from RJC or MI, whether you already have your own private tutor or have no tuition at all. You just need to register an SgForums account (it's free!), and you get to enjoy the benefit of getting high quality, trustworthy and reliable help with your Chemistry questions free-of-charge.
Terms & Conditions : Only genuine and reasonable questions from genuine and reasonable students asked in a genuinely and reasonably respectful manner will be replied to. And you should post your own attempted answers, and/or the given answers, and/or your queries on specifically what you don't understand about the question or don't agree with the given answers. I won't do your homework for you, instead I'll comment, guide and advise you on your question.
2018 JC1 & JC2 students, do use SgForums to support your studies. And if you haven't yet made an SgForum account, you can go ahead and do so now. Post any H2 Chemistry questions you have here in this thread.
From the number of views my H2 Chemistry threads on this forum has garnered, it's pretty clear that hundreds of lurkers (presumably and hopefully the majority of whom are actual JC students) are interested in my H2 Chemistry posts.
Well, to all you lurkers out there (especially if you're a genuine JC student), here's a suggestion : Why don't *you* go ahead and make a SgForums account so you can post your own H2 Chemistry queries here.
Just register an account with SgForums, it's easy and free (of course, asking for free online help here... or for that matter anywhere... isn't as effective as actually joining my BedokFunland JC tuition, but it's still better than having no one reliable to ask for help... or if you disagree with your own private tutor or school teacher and wish to have a 2nd opinion that's reliable and trustworthy) to ask anything relevant to H2 Chemistry here.
For instance, if you wish to discuss a TYS qn or a JC Prelim qn (eg. if you don't understand or disagree with the answer given by the TYS author, or the prelim paper's mark scheme, or your school teacher's explanation. etc), you can just specify the question (eg. "2016 RJC P3 Q2" or "TYS 2015 P3 Q2" etc) and ask your question. If it's a non-TYS qn or non-Prelim qn that involves a diagram, you'll have to use your handphone to take a photo, and upload the image to your Facebook, Twitter, blog, etc, and link to the image in your post.
New members of SgForums won't be able to start new threads until you've reached a certain post count, so go ahead and post your H2 Chem qns in this thread till then. -
Less people ask Physics questions nowadays
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Originally posted by eagle:
Less people ask Physics questions nowadays
You can post more Physics stuff on the forums more frequently lor. Even if they just lurk and read your posts without replying or posting, at least that may help encourage visitors (occasional visitors may not know there is a Physics expert here, ie. you, that they can seek help from) to be more willing to register an SgForums account to post and ask for help with their Physics questions here.For some of you lurkers who may not know, Eagle runs his own tuition center, that you can consider if you're looking for a tuition center for your O and A level needs :
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i love chem
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I love chem :3
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Everyone loves Chemistry, it's true.
I encourage every single JC student in Singapore (from MI to RJC) who doesn't already have private tuition to register an SgForum account here, to ask for help here on H2 Chemistry questions for FREE !!!
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A BedokFunland JC H2 Chemistry Qn
How would the rate of a reaction that is -(1/2) order with respect to a particular reactant, change if you
(i) increase the molarity of that reactant by 1/2?
(ii) decrease the molarity of that reactant by 1/2? -
[Medical] - Medical Doctor David Gorski angrily disagrees with Biochemistry Professor Christopher Exley on Whether the Aluminium in Vaccines causes Autism
There is no simple right and wrong. Both make valid points. There is increasing medical evidence that aluminium contributes to brain damage. What Dr David Gorski disagrees with, is whether the aluminium in vaccines is a significant source of aluminium toxicity (since some argue that aluminium exposure from foods and environment, is even worse than from vaccines), and therefore whether the risks of vaccinations outweigh the rewards.
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A couple of 2018 BedokFunland JC H2 Chemistry Qns :
Potassium metal cannot be effectively obtained from the electrolysis of molten salts such as potassium chloride. Why? Accordingly, suggest an alternative setup to successfully obtain potassium metal.
Full Question here : http://www.bedokfunlandjc.com/#Qns
During the extraction of sodium metal via electrolysis, often a molten mixture of sodium chloride and calcium chloride is used, instead of pure sodium chloride. Suggest why, and what problems would occur if pure sodium chloride was used instead.
Full Question here : http://www.bedokfunlandjc.com/#Qns
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I will take a crack at the two Group I metals' problems, if you don't mind. Appreciate any feedback.
1. Since K is soluble in KCl (l), you can try adding in Na to the molten KCl salt (~850 C). K (bp 760 C) is more voltatile than Na (bp 883 C), so it can be distilled off, and by Le Chatelier's principle, as K is being removed, more KCl reacts to form NaCl.
KCl (l) + Na (l) = NaCl (l) + K (g)
This is the principal method for the industrial production of K, I believe.
2. Your second question of electrolysis of NaCl + CaCl2 is basically the Downs process.
i. The mixture of the two salts can form an eutectic mixture, lowering the melting point. NaCl melts at 801 C, and by mixing in CaCl2, you can lower the melting point to a much lower temperature of around 600 C. This point matters because pure Na boils at 883 C. (see point iii below)
ii. If based on the Data Booklet, Na+ (-2.71V) preferentially reduces rather than Ca2+ (-2.87V).
iii. If no CaCl2 is added, then any Na that is formed from NaCl will form a metallic gaseous cloud because of the small temperature diference between molten NaCl and Na(g). This makes it hard to extract and remove the Na metal.
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Originally posted by tk2018:
I will take a crack at the two Group I metals' problems, if you don't mind. Appreciate any feedback.
1. Since K is soluble in KCl (l), you can try adding in Na to the molten KCl salt (~850 C). K (bp 760 C) is more voltatile than Na (bp 883 C), so it can be distilled off, and by Le Chatelier's principle, as K is being removed, more KCl reacts to form NaCl.
KCl (l) + Na (l) = NaCl (l) + K (g)
This is the principal method for the industrial production of K, I believe.
2. Your second question of electrolysis of NaCl + CaCl2 is basically the Downs process.
i. The mixture of the two salts can form an eutectic mixture, lowering the melting point. NaCl melts at 801 C, and by mixing in CaCl2, you can lower the melting point to a much lower temperature of around 600 C. This point matters because pure Na boils at 883 C. (see point iii below)
ii. If based on the Data Booklet, Na+ (-2.71V) preferentially reduces rather than Ca2+ (-2.87V).
iii. If no CaCl2 is added, then any Na that is formed from NaCl will form a metallic gaseous cloud because of the small temperature diference between molten NaCl and Na(g). This makes it hard to extract and remove the Na metal.
Yes, very good. All correct.Are you a school teacher or private tutor? An undergrad or grad?
Ya know, in every instance in past years, almost every SgForums member who correctly answered my BedokFunland JC Questions (eg. the guy who correctly answered my BedokFunland JC OC Deductive Elucidation Qns a few months back), will claim they are currently just JC students (some will even specify "neighbourhood JC student" ), when I ask them who they are.
Obviously I know they're not JC students, but since they want to insist they are, I just play along and pretend they are.
So, are you going to say you're a 'neighbourhood JC student' as well? ;Þ
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Btw, the previous post was made in good humour. No offence intended.
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No offence taken. I also never claim that I am a JC student (neighbourhood or otherwise). 'Was' will be more appropriate. :)
Your Bedok Funland questions are interesting, and quite solvable only if the students read widely. Unfortunately, many are swamped with school work and many don't read outside of syllabus. They also need a certain degree of interest in Chemistry to read beyond their school/tuition notes.
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Originally posted by tk2018:
No offence taken. I also never claim that I am a JC student (neighbourhood or otherwise). 'Was' will be more appropriate. :)
Your Bedok Funland questions are interesting, and quite solvable only if the students read widely. Unfortunately, many are swamped with school work and many don't read outside of syllabus. They also need a certain degree of interest in Chemistry to read beyond their school/tuition notes.
Cool. I appreciate honesty.Assuming you'll be hanging out on the this forum (I noticed you made an SgForums account for this), mind if I ask again : Are you a school teacher or private tutor? An undergrad or postgrad?
Of course, you don't need to answer if you don't want to. Just that, it's nice to know who I'm talking to (especially if you'll be hanging out here).
And as I've stated elsewhere, I'll much prefer a fellow private tutor honestly say he's one, than masquerade as a current JC student (not you, some other chaps).
Given your interest in my Chem qns, it's safe to surmise you're either a private Chem tutor, or currently a Chem undergrad? Or school Chem teacher or Chem postgrad?
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I always find these "So what do you do? What is your background?" kind of questions like some kind of d*ck-measuring contest or pissing match. Pardon the vulgarities (definitely not directed at you), and don't mind me, those are just the first thoughts that come into my mind when I see them :). Especially in the Singapore context. It seems hard to be a "Good Will Hunting" kind of chap to come in and solve difficult academic problems.
Well, since this is the internet (i.e. we can be anyone we say we are), I taught undergraduate chemistry modules in the mecca of science that is by the banks of Charles River, and a hippie town known for drunken revelry and rioting in CA, so hopefully that qualifies me to post suggested answers on this forum! I stumbled into this forum because it's rare to see a Singapore homework forum with high-school/A-level chemistry questions that matched the difficulty of some of my sophomore level classes. Kudos to you!
I still find my A level Chemistry (especially the old S-paper) days to be most memorable, because of a teacher who made me think and challenged me in the subject rather than spoonfeeding.
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Originally posted by tk2018:
I always find these "So what do you do? What is your background?" kind of questions like some kind of d*ck-measuring contest or pissing match. Pardon the vulgarities (definitely not directed at you), and don't mind me, those are just the first thoughts that come into my mind when I see them :). Especially in the Singapore context. It seems hard to be a "Good Will Hunting" kind of chap to come in and solve difficult academic problems.
Well, since this is the internet (i.e. we can be anyone we say we are), I taught undergraduate chemistry modules in the mecca of science that is by the banks of Charles River, and a hippie town known for drunken revelry and rioting in CA, so hopefully that qualifies me to post suggested answers on this forum! I stumbled into this forum because it's rare to see a Singapore homework forum with high-school/A-level chemistry questions that matched the difficulty of some of my sophomore level classes. Kudos to you!
I still find my A level Chemistry (especially the old S-paper) days to be most memorable, because of a teacher who made me think and challenged me in the subject rather than spoonfeeding.
Appreciate your candour. Thanks for being honest about your Chem postgrad background.As you say this is the internet (though from a review of one's postings, one can more or less deduce the truthfulness of one's professed identity, eg. nayr69sg does appear to be a real Singaporean medical doctor who is currently practicing medicine in Canada), but I still routinely ask a new SgForum member's background and current profession (which I noticed you've sidestepped, eg. whether you're currently a Chem private tutor or Chem MOE school teacher, but I'll leave it to you whether you wish to share on this), when I notice unusual posts (eg. if the content of the posts clearly indicate the poster is almost definitely not a JC student, this simple fact can be used to assess the honesty of the person by asking the person's background, and 4/5 times I get the less-than-honest response, "I'm just a neighbourhood JC student lah", ok lor if u say so...), and this (my asking the poster's background), is not so much for measuring dicks, but rather that, if the poster (ie. the person I'm talking to) turns out to not actually be a current JC student (the poster being a JC student is a reasonable initial assumption since this forum is for current JC students to ask me for help), and instead turns out that the poster (ie. any newcomer who responds to my Chem qns or asks me Chem qns) is actually currently an undergrad or post grad or fellow private tutor or MOE school teacher, then it would be wholly inappropriate (rude even) for me to appear condescending and 'talk-down' to the poster (ie. when discussing Chemistry concepts, eg. If I replied you with a "Go google or ask your school teacher on the definition of such-and-such, then get back to me with your revised answer", which would be pedagogically appropriate if you are indeed a JC student, on the other hand would naturally be offensive if you're an undergrad or post grad or fellow private tutor or MOE school teacher, something I'd rather avoid, which is why I ask of the person's background and current profession, and hope to receive an honest response.
Indeed, the 1 out of 5 respondents in past years, a mere handful, did reply me (sometimes through private messaging), to say they are currently an undergrad or post grad or fellow private tutor or MOE school teacher, I appreciated their candour. And it made me all the more willing to help them with their Chem questions, and with more level-appropriate replies, eg. "I'd suggest you advise your students to do it this way...".
All in all, tk2018 (whether you're currently an MOE teacher or private tutor or something else altogether), welcome to SgForums, and you're welcome to join me in advising and helping out Singapore JC students with their questions, although in all honesty, you'll probably be disappointed and bored with this forum, because business is slow (ie. not many JC students ask for help here), despite my sincere hopes that all Singapore JC students who can't afford private tuition, register an SgForums account to receive help with their JC subjects here (other than myself and Chemguide7 for Chemistry, Wee_Ws helps out for Mathematics, Eagle helps out for Physics and Mathematics, and Darkness_hacker99 helps out for Biology, but business (ie. students asking qns) has been so slow in recent years, that these folks only drop occasionally these days, if at all.
tk2018, if you do have your own Chemistry website, or blog, even if it's your own private tuition website, if it contains useful materials for students, not necessarily study notes, can be a collection of links to interesting Chemistry articles etc, feel free to post your url here to share with JC students (from the logged statistics, the vast majority of visitors to this forum are lurkers, and while there are certainly many private tutors and school teachers lurking here, I'll like to think that there are many genuine JC students visiting here as well, and would like to encourage them to register an SgForums account to get help for their A level subjects here, especially if they cannot afford private tuition).
Mr Chong (Chemguide7)'s H2 Chemistry website :
http://www.alevelchemistrysg.com/My BedokFunland JC website :
http://www.bedokfunlandjc.com/ -
Hi UltimaOnline,
Thank you for remembering me. Hello to tk2018 as well.
All the best to you all in 2018 and have a happy New Year!!
Thanks to UltimaOnline for answering so many of students' queries.
Cheers!!
Mr Chong
ex-JC chemistry tutor
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Originally posted by Chemguide7:
Hi UltimaOnline,
Thank you for remembering me. Hello to tk2018 as well.
All the best to you all in 2018 and have a happy New Year!!
Thanks to UltimaOnline for answering so many of students' queries.
Cheers!!
Mr Chong
ex-JC chemistry tutor
Hi Mr Chong,May 2018 be a kinder year to us and to all. Cheers!!!
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Originally posted by UltimaOnline:
Appreciate your candour. Thanks for being honest about your Chem postgrad background.As you say this is the internet (though from a review of one's postings, one can more or less deduce the truthfulness of one's professed identity, eg. nayr69sg does appear to be a real Singaporean medical doctor who is currently practicing medicine in Canada), but I still routinely ask a new SgForum member's background and current profession (which I noticed you've sidestepped, eg. whether you're currently a Chem private tutor or Chem MOE school teacher, but I'll leave it to you whether you wish to share on this), when I notice unusual posts (eg. if the content of the posts clearly indicate the poster is almost definitely not a JC student, this simple fact can be used to assess the honesty of the person by asking the person's background, and 4/5 times I get the less-than-honest response, "I'm just a neighbourhood JC student lah", ok lor if u say so...), and this (my asking the poster's background), is not so much for measuring dicks, but rather that, if the poster (ie. the person I'm talking to) turns out to not actually be a current JC student (the poster being a JC student is a reasonable initial assumption since this forum is for current JC students to ask me for help), and instead turns out that the poster (ie. any newcomer who responds to my Chem qns or asks me Chem qns) is actually currently an undergrad or post grad or fellow private tutor or MOE school teacher, then it would be wholly inappropriate (rude even) for me to appear condescending and 'talk-down' to the poster (ie. when discussing Chemistry concepts, eg. If I replied you with a "Go google or ask your school teacher on the definition of such-and-such, then get back to me with your revised answer", which would be pedagogically appropriate if you are indeed a JC student, on the other hand would naturally be offensive if you're an undergrad or post grad or fellow private tutor or MOE school teacher, something I'd rather avoid, which is why I ask of the person's background and current profession, and hope to receive an honest response.
Indeed, the 1 out of 5 respondents in past years, a mere handful, did reply me (sometimes through private messaging), to say they are currently an undergrad or post grad or fellow private tutor or MOE school teacher, I appreciated their candour. And it made me all the more willing to help them with their Chem questions, and with more level-appropriate replies, eg. "I'd suggest you advise your students to do it this way...".
All in all, tk2018 (whether you're currently an MOE teacher or private tutor or something else altogether), welcome to SgForums, and you're welcome to join me in advising and helping out Singapore JC students with their questions, although in all honesty, you'll probably be disappointed and bored with this forum, because business is slow (ie. not many JC students ask for help here), despite my sincere hopes that all Singapore JC students who can't afford private tuition, register an SgForums account to receive help with their JC subjects here (other than myself and Chemguide7 for Chemistry, Wee_Ws helps out for Mathematics, Eagle helps out for Physics and Mathematics, and Darkness_hacker99 helps out for Biology, but business (ie. students asking qns) has been so slow in recent years, that these folks only drop occasionally these days, if at all.
tk2018, if you do have your own Chemistry website, or blog, even if it's your own private tuition website, if it contains useful materials for students, not necessarily study notes, can be a collection of links to interesting Chemistry articles etc, feel free to post your url here to share with JC students (from the logged statistics, the vast majority of visitors to this forum are lurkers, and while there are certainly many private tutors and school teachers lurking here, I'll like to think that there are many genuine JC students visiting here as well, and would like to encourage them to register an SgForums account to get help for their A level subjects here, especially if they cannot afford private tuition).
Mr Chong (Chemguide7)'s H2 Chemistry website :
http://www.alevelchemistrysg.com/My BedokFunland JC website :
http://www.bedokfunlandjc.com/Thanks UltimaOnline for your kind words. I don't just help with A level Chemistry questions. I am also interested in trying to help students aim to get into the better universities/courses. Managed to get one of my students a university scholarship offer.
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Originally posted by tk2018:
Thanks UltimaOnline for your kind words. I don't just help with A level Chemistry questions. I am also interested in trying to help students aim to get into the better universities/courses. Managed to get one of my students a university scholarship offer.
You referring to your MOE school student or your private tuition student (it'll be easier to communicate if we just get this out in the open)?So you teach / tutor others subjects other than Chemistry? What other subjects do you help out with? And can help out with on this forum?
So how would you help SgForum students "get into the better universities/courses"? You wish to offer your services in advising and counselling students on academic pathways? Here on SgForums, or specifically helping your own school / private tuition students?
No offence with all these questions, just that it would help facilitate clearer communication if we have a better idea of exactly what you're offering or intending to offer, specifically via this forum.
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1. My private tution student. I do this part time; I have a full time job elsewhere.
2. No, my focus is chemistry.
3. Not offering any paid services via this forum. Prefer to be anonymous for now. What I meant was students can post general questions on how/what to do when it comes to scholarships/universities' applications; if the questions can be answered on the forums.
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Originally posted by tk2018:
1. My private tution student. I do this part time; I have a full time job elsewhere.
2. No, my focus is chemistry.
3. Not offering any paid services via this forum. Prefer to be anonymous for now. What I meant was students can post general questions on how/what to do when it comes to scholarships/universities' applications; if the questions can be answered on the forums.
Understood, thanks for your reply and sharing, appreciate it."Students can post general questions on how/what to do when it comes to scholarships/universities' applications; if the questions can be answered on the forums."
Thanks in advance for your willingness to help out students with their questions on their further education. I hope many JC students will take up your kind offer, register an SgForums account and post their further education queries here.
:)
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The following MCQ is a Cambridge A level MCQ, used in both the UK and Singapore papers.
When iron reacts with aqueous iron(III) ions, iron(II) ions are formed as the only product. A final mixture, after the reaction has taken place, contains equal numbers of moles of Fe2+(aq) and Fe3+(aq). Assuming the reaction has gone to completion, how many moles of Fe(s) and Fe3+(aq) were in the starting mixture?
I remember coming across a Singapore JC Prelim / Tutorial MCQ which used this MCQ and gave it a twist to make it tougher. I searched for it but can't find it. If anyone recognizes the Singapore JC Prelim / Tutorial MCQ I'm referring to, please post the JC and year, or the MCQ itself, thanks.