O-Level Chemistry

[sergeykang]

I see. Thanks for the advice!


Have you heard of The Physics and Maths Cafe? I’ve heard that they teach Sec/JC Chem as well. I’m not sure if they’re good tbh.

[sergeykang]

https://www.pmc.sg/

This one right? Their fees seem really expensive. I can afford it, but I'm not sure if their classes are worth the money tbh.

Edit: Eh? Physics Maths Cafe got two websites?! I'm abit confused. :scared:

As for uptas, hmm. I'll take some time to think about it.

[sergeykang]

From their website it seems that PMC offers trial classes as well.

Anyway thank you so much for your insights! I'll take both centres into consideration then.

Meanwhile I'll just ask around here to see if anyone else has enrolled their children in those centres.

[MerlionInGermany]

sergeykang\" post_id=\"1967106\" time=\"1584235313\" user_id=\"184588:

https://www.pmc.sg/
This one right? Their fees seem really expensive. I can afford it, but I'm not sure if their classes are worth the money tbh.

Edit: Eh? Physics Maths Cafe got two websites?! I'm abit confused. :scared:

As for uptas, hmm. I'll take some time to think about it.

I think when it was said “i’ll send you the link in a while”, it meant the uptas link that he’s trying to promote. Apparently there is some publicity here, from this center recently. But didnt want to be appear too in-your-face by sending the link immediately, so “will send in a while after checking kids notes”.

Is the PMC fees on the website?

[sergeykang]

My apologies, I misread what brues said.

Anyway thanks for your help.

[Maggie85]

Me, i would suggest you go first for those who give free trial classes. Good if you can try on different tuition so you can assess which one is effective and fits well to your kids.

[bestwishes]

The answer is in the Chem textbook, Topic electrolysis

[bestwishes]

achun708\" post_id=\"1967260\" time=\"1584339352\" user_id=\"184516:

Hello Everyone,

Can you please help me with this? My son is a bit confused with this problem and me too. Thanks.

Predict the products formed (i) at the cathode, (II) at the anode, when copper (II) sulfate solution is electrolysed using carbon electrodes.

The answers can be found in Chem Matters textbook. Topic electrolysis pg 293

[Nefertari]

Yep, the answer is in the Chem Matters textbook. Or you can ask everybody's best friend Google:


http://www.docbrown.info/page01/ExIndChem/electrochemistry04.htm

Electrolysis of copper sulphate using carbon (graphite) electrodes vs using copper electrodes . It's a typical case study (so bascially, you need to understand the full process).

Few things to note in electrolysis:
1. Cations are attracted to the cathode and anions are attracted to the anode.
2. Electrolysis requires electricity flowing through the electrodes to split up the electrolytes (conducting liquid containing the compound, eg copper sulphate).
3. Is the electrode used inert or does it react with the electrolyte?

In the case of copper sulphate, what occurs at the cathode is simple and straightforward: COPPER is deposited ON the cathode (negative terminal) due to as the Cu2+ ions get reduced and becomes neutral copper atoms.

At the anode, two scenarios can occur. If the electrode is copper, it is reactive with the sulphate ions that are attracted to the copper anode and thus the copper anode dissolved. However, the question states that CARBON (inert electrodes) are used, therefore the sulphate ions (produced during the electrolysis) attracted at the anode remains stable. What you get are hydroxide ions (which are also attracted to the anode) getting oxidised to discharge water molecules and also form oxygen.

Just read it a couple more times and it will come to you. Cheers!

[Nefertari]

Metanoia\" post_id=\"1799756\" time=\"1504704412\" user_id=\"128527:

kitty2:

[quote=\"Metanoia\"]
Hi there, to clarify, are you referring to the school-based Science Practical Assessment taken by Pure chemistry students or the Science Practical Exams taken by combined chemistry students?

Is for combine science students . Thanks

Combined chemistry students will most likely be doing identification of unknown ions.

1) It will be useful for the student to be familiar with this reference table.
It is page 36 in this document.

http://www.seab.gov.sg/content/syllabus/olevel/2017Syllabus/5078_2017.pdf

This table will be provided during the practical, but I'll encourage them to be familiar with it before hand rather than try to make sense of it during the test itself.

2) Basically, the test consists of following the instructions, writing down the observations and making conclusions.
Writing observations - the student can use the relevant phrases described in the table
Making conclusions - this part is largely dependent on the observations.

Students are usually stressed about making the conclusion but keeping things in perspective. The chemistry practical is \"only 7.5%\" and the conclusion part is an only small portion. There are more marks to make up for it in the theory papers.

3) The questions are quite varied, so I will not try to \"predict\" anything more specific. I've seen past year papers on O-level practicals available in the bookshop, you can buy them to have a sense of the questions.
If however, you have specific questions, feel free to clarify.[/quote]This is a very good post. Two thumbs up