wooyin08\" post_id=\"1977670\" time=\"1590384582\" user_id=\"185522:

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!

colleencwc\" post_id=\"1971300\" time=\"1586954974\" user_id=\"11391:

Hi, I am looking for P6 & Sec 4 courses.
P6 -- Science, English & Chinese
Sec 4 -- English, E-Maths, A-Maths , Chemistry & Biology
Thanks!

Hi colleen,

I've sent you PM for Sec 4 Chem.
We have free trial class for Chem. Can reply to PM for more detials.

Thanks,
UPTAS

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!

leeh40\" post_id=\"1977140\" time=\"1590061422\" user_id=\"185343:

uptas\" post_id=\"1977132\" time=\"1590057338\" user_id=\"184429:

[quote=leeh40 post_id=1977017 time=1590034490 user_id=185343]Hi,

What is the effect of impurities in melting point and boiling point of a substance? Need your help. Thanks.

Hi lee!

Impurities cause lowering of melting point through the process called melting point depression. For the boiling point, on the other hand, impurities results to higher boiling point of the substance because the number of molecules available for boiling is decreased.

I hope it helps!

If you have more assignments to be assisted with, you can post at this forum. https://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=29&t=95661&p=1973791#p1973791
you can also find Q&A and tips and tricks there!

Why is the impurities causing the melting point to decrease? For the boiling point, thank you so much Uptas for the rationale.

Will visit the forum you have shared for my next queries. Thanks a lot![/quote]hi Lee,

Impurities can cause a melting point depression because impurity disrupts the crystal lattice energies.

Hope it helps!

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.

leeh40\" post_id=\"1977017\" time=\"1590034490\" user_id=\"185343:

Hi,

What is the effect of impurities in melting point and boiling point of a substance? Need your help. Thanks.

Hi lee!

Impurities cause lowering of melting point through the process called melting point depression. For the boiling point, on the other hand, impurities results to higher boiling point of the substance because the number of molecules available for boiling is decreased.

I hope it helps!

If you have more assignments to be assisted with, you can post at this forum. https://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=29&t=95661&p=1973791#p1973791
you can also find Q&A and tips and tricks there!

playing UNO cards is also fun. and well, the classic chess is also entertaining at the same time, it exercises your brain

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?
\t Anode\t Cathode
A\t Oxygen Copper
B\t Hydrogen\tOxygen
C\t Copper\t Hydrogen
D\t Oxygen\tHydrogen

Answer: A

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

You’re most welcome chay!


We’re really looking out to help kids in their Chemistry studies, especially this HBL.
We hope to share more Tips and tricks and Q&As to you in order to help you develop your passion for Chemistry.

Watch out for more of our posts!

Cheers!

Hey there Students and parents!


We hope you have started doing the review for the upcoming exams. 5 months preparation time is a great start as you can have a long time to decipher how your study habits look. You can have enough time to assess what kind of reviewing is effective for you or not.

anyways, for today, we are sharing with you a Q&A on ACIDS and BASES topic.

Which compound should not be used to prepare magnesium chloride by reaction with hydrochloric acid?

A. Magnesium\t\t\t\tB. Magnesium oxide
C. Magnesium nitrate\t\t\tD. Magnesium carbonate\t\t

Answer: C

Explanation: Magnesium chloride is a soluble salt and is prepared by reaction of acids with either a metal, base or carbonate. There is no visible reaction between magnesium nitrate and hydrochloric acid. There is also no undissolved solid left to indicate that all the acid has reacted.