Chemistry Trivia (Q&A and some tips and tricks)

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uptas
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by uptas » Tue May 19, 2020 7:21 pm

Hey there parents!

Are you helping your kids in their revisions review? just visit this forum to have something Q&A or tips and tricks to share with them.

For tonight, we are opening a new topic on electrolysis. Starting off with this question.

What are the products at the electrodes when an aqueous solution of copper(II) sulfate is electrolysed using carbon electrodes?
Anode Cathode
A Oxygen Copper
B Hydrogen Oxygen
C Copper Hydrogen
D Oxygen Hydrogen

Answer: A

Explanation: Water is preferentially discharged at the anode to form oxygen, while copper is deposited on the cathode.

uptas
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by uptas » Thu May 21, 2020 7:55 pm

Hi parents and students!

SHaring you some notes on REDOX.
Here's a list of the common oxidising agents

MnO4– is reduced to Mn2+ under acidic conditions.

Cr2O72– is reduced to Cr3+ under acidic conditions.

Halogens are reduced to halides.

Fe3+ is reduced to Fe2+.

H2O2 is reduced to H2O.

uptas
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by uptas » Sun May 24, 2020 8:28 am

Hey there parents/students,

TO compliment the previous post, here are the common redusing agents and how they become such in Redox reactions.

Fe2+ is oxidised to Fe3+.

H2O2 is oxidised to O2.

Halides are oxidised to halogens.

C2O42– is oxidised to CO2.

S2O32– is oxidised to S4O62– by I2 and to SO42– by other stronger oxidising agents like Cl2.

FeC2O4 is oxidised to CO2 and Fe3+.

Wishing you all the best in your reviews!

PM us if you wish to have a copy of these notes, compiled!

wooyin08
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by wooyin08 » Mon May 25, 2020 1:29 pm

Hello,

I'm new in Kiasu and I purposedly created my account hoping I can find a venue where I can ask help for my studies since my parents cannot afford to get a tuition for myself. Then came across with this thread so now I'd like to try if I can get help here..

I have this problem in my Chemistry and not so confident with my answer yet.

When potassium chlorate(V) KClO3, is heated at its melting point, it disproportionates to potassium chlorate(VII) KClO4 and potassium chloride.

What is the maximum number of moles of potassium chlorate(VII) which could
be produced from 0.1 mol of potassium chlorate(V)?

Thanks.

wooyin08
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by wooyin08 » Mon May 25, 2020 1:58 pm

uptas wrote:
Thu May 21, 2020 7:55 pm
Hi parents and students!

SHaring you some notes on REDOX.
Here's a list of the common oxidising agents

MnO4– is reduced to Mn2+ under acidic conditions.

Cr2O72– is reduced to Cr3+ under acidic conditions.

Halogens are reduced to halides.

Fe3+ is reduced to Fe2+.

H2O2 is reduced to H2O.

Hello,

Thanks for sharing these. But, can substances act as both oxidizing agents and reducing agents? If yes, can you show us an example. Thanks!


uptas
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by uptas » Mon May 25, 2020 5:19 pm

wooyin08 wrote:
Mon May 25, 2020 1:29 pm
Hello,

I'm new in Kiasu and I purposedly created my account hoping I can find a venue where I can ask help for my studies since my parents cannot afford to get a tuition for myself. Then came across with this thread so now I'd like to try if I can get help here..

I have this problem in my Chemistry and not so confident with my answer yet.

When potassium chlorate(V) KClO3, is heated at its melting point, it disproportionates to potassium chlorate(VII) KClO4 and potassium chloride.

What is the maximum number of moles of potassium chlorate(VII) which could
be produced from 0.1 mol of potassium chlorate(V)?

Thanks.
Hi wooyin,

Given your circumstance, may I know if you are in Sec or JC? So I'll know where you could get the best help.

Thanks for having great time scanning through this forum!

uptas
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by uptas » Thu May 28, 2020 9:46 am

hey there students and parents!


I know some of you have started revising. I hope this forum have helped you with it.
For today, let's review some periodic table arrangement patterns.

Which of the following properties is used to arrange elements in the Periodic Table?
A. Reactivity B. Mass number
C. Atomic number D. Neutron number

Answer: C

Explanation: The elements are arranged according to the number of protons in the nucleus, i.e., the atomic number.

uptas
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by uptas » Thu May 28, 2020 9:48 am

Here's another periodic table interpretation trick in "guessing" the state of the element in the environment.

Which of the following would be a solid at room temperature?
A. Xenon B. Radon
C. Astatine D. Bromine

Answer: C

Explanation: Astatine is below iodine in the Group VII. Iodine is a solid and, by deduction, astatine would also be a solid. All the other options are elements in gaseous state.

chay58
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by chay58 » Fri May 29, 2020 11:28 am

Hi there!

I don't know if I landed the appropriate forum but may I ask if you have assessment books? or do you have an idea where I could find a most recent assessment books?

Thanks!

uptas
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Re: Chemistry Trivia (Q&A and some tips and tricks)

Post by uptas » Sun May 31, 2020 6:22 pm

chay58 wrote:
Fri May 29, 2020 11:28 am
Hi there!

I don't know if I landed the appropriate forum but may I ask if you have assessment books? or do you have an idea where I could find a most recent assessment books?

Thanks!
Hi chay58,

I'll be sending you PM for details on this.

Regards,
UPTAS

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