(7th of 19 Chapters) Acids, Bases, Oxides & Ionic Equations - GCE O Level Chemistry Lecture

[@mustafafaisal110]

you are an absolute legend. I don't have words to thank you. it's people like you who give humanity hope. excellent all around.

[@ChemLectures]

+Mustafa Faisal thanks. glad you found the videos useful. let more of your friends know if you think it'll help them too.

[@ChemLectures]

Note that at 1:15.08, there is an error. Acidic oxides should be non-metal oxides and basic oxides should be metal oxides. the subsequent slide which explains this is correct.

[@sun-ox3bt]

are u a cher in cat high now? how i wish i was a guy n in cat high too !! HAHA

[@ChemLectures]

not in cat high already. anyway, all schs are good, just make sure u listen critically in class and qn ur teacher

[@usmanmirza897]

Thanks sir very much useful

[@shayansaleem1023]

Thank you 😊 This helped me a lot in revising all the previous concepts!!

[@ChemLectures]

+Shayan Saleem welcome!

[@anumsajid4770]

hello! I am from pakistan and going to get appear in May/June 2019 examinations...your videos are helping me alot ... These lectures are very beneficial for revising all the chemistry olevels concepts ...Thnx for these perfect and amazing lectures...May God bless u

[@ChemLectures]

glad you found them useful!

[@ABDULREHMAN-rb5tk]

HOW IS YOUR PREPARATION I AM ALSO GOING FOR 2019 EXAMINATION IN PAKISTAN AND TY TO HIS VIDEOS I AM ABLE TO PREPARE 2 DAYS BEFORE AND

[@ABDULREHMAN-rb5tk]

HOW IS YOUR PREPARATION I AM ALSO GOING FOR 2019 EXAMINATION IN PAKISTAN AND TY TO HIS VIDEOS I AM ABLE TO PREPARE 2 DAYS BEFORE AND

[@fatimaazad]

thank u so much ......this helped tonnes...May God bless u...kepp up ...and do other vdeos in other subjects ...like physics ...bio...maths :D

[@nabeelahmed2619]

I just enjoyed it much! very good presentation ♥

[@ChemLectures]

+Nabeel Ahmed thank you

[@jmusikwi4061]

this is exceptionally good Mr. Lecturer. be blessed

[@ChemLectures]

Thanks, you too!

[@afiqah157]

Good Morning. I'd like to clarify this mcq related qns that I'm unsure of. Qns: Which compound should a farmer add to neutralize soil that has a pH of 3? b) potassium hydroxide d) calcium carbonate My chem teacher told me that the answer is (d) but I'm still unsure of why isnt the ans (c) as when a base reacts with acid, it neutralises the acid. Furthermore, it's straightforward that we're able to see that hydroxide is a base. Your explanation would really help me a lot. Thank you.

[@ChemLectures]

I see. You are right to have noticed that you will need something to raise the pH of the soil. Theoretically, both KOH and CaCO3 can do the trick, as they both react with H+ ions and remove them. HOWEVER, there is one key difference between KOH and CaCO3. KOH is a strong base. CaCO3, on the other hand, cannot dissolve in water, hence it is effectively neutral. This means that if the farmer adds too much KOH, the soil will end up being too alkaline now. However, if he adds too much CaCO3, nothing will happen. The CaCO3 will react with the H+ ions in the soil, and any excess will just remain as solid CaCO3. Hope this helps.

[@afiqah157]

Thank you for your help (: One more question. How do we know if a compound is a strong base or a weak base? Thank you for taking your time off to reply (:

[@ChemLectures]

for the syllabus, the metal hydroxides and the soluble metal oxides are strong bases eg KOH, NaOH. the rest are usually weak bases.

[@robinsonchiwama3311]

Your lessons are very educative and very easy to understand. My regards to you all.

[@ChemLectures]

Thanks. Do let your friends know if it has helped

[@john36138]

Coherent and extremely helpful. Thank you

[@ChemLectures]

Mark Anthony Henry Thank you.

[@firstnamelastname754]

Bro you are saving lives to this day 😂😂🙂😃

[@cyberalpha5740]

in checkpoint 7, part 1 c ,isn't calcium sulphate insoluble in water, thus it shouldn't be broken down into two ions .

[@ChemLectures]

calcium sulfate is sparingly soluble. a little can dissolve.

[@usmanadnan8716]

This is really comprehensive. Thank you for your help. If possible do you mind doing past paper questions as well. Thank you!

[@ChemLectures]

Usman Adnan Q&A is in the process of recording

[@kalaalieric4877]

thank you SIR for this wonderful understandable lesson i like it

[@ChemLectures]

Thanks

[@intisarillhammasud6038]

34:20 Leaving a time stamp so i can continue later

[@alizarqaash]

Thank you sir you are great and you have done great. I am proud of you. It is true that you are legendary. Excellent all around.😄😇😉

[@ChemLectures]

Thanks

[@sarahjawaid8921]

Sir Chua, where can I get your notes from? I'd be thankful if you answer me

[@ChemLectures]

www.chemlectures.sg or www.chemistrylectures.com

[@shamimlawrence9841]

Thank you very much sir for your help.Its really use full

[@ChemLectures]

welcome

[@hamzamoosa2375]

I love them :) Extremely Helpful Thankyou so much !

[@hellboy9129]

thanks for the lesson it was very help full

[@ChemLectures]

welcome

[@cherylchong3967]

hi sir, i was just wondering, calcium sulfate state symbol is a solid,yes?

[@ChemLectures]

yes it is

[@ahmedshaikh2221]

What does mean by virtual test sir on 2and April Iam having my test due to corona pandemic this will decide my grade

[@yongkhin9915]

thank you very much!!!

[@Euchuan]

Question C of the ionic eqn Ca(OH)2 + H2SO4> CaSO4 + 2H20 CaSO4 is insoluble. so shldnt it be solid?

[@ace6929]

i thought so too.

[@kzdwt9969]

49.30 metals as in only cations? or?

[@aneeqkhan8627]

you're a life saver

[@ChemLectures]

+Aneeq Khan thanks

[@ritishachawla4387]

Plz plz approve my request for notes and I want to thank u for these notes... U saved my exams

[@samaraz6984]

Thank u soo much this is really good

[@ChemLectures]

glad you found it useful

[@imameatball7482]

Thank you!!

[@pixpixpix394]

Also thankyou for these. They help a lot!

[@ChemLectures]

welcome. glad you found this useful

[@mariashabbir5810]

You teach very wellllllll❤❤

[@ChemLectures]

Thank you! 😃

[@infjkairosclerosis]

lol Mr Chua Tung Kian needs to know that i'm watching his videos 8 years later hahah

[@labibsalehin7182]

May God Bless you. Excellent notes. Really Extraordinary.

[@ChemLectures]

Labib Salehin thanks. do share with you friends the website and youtube channel

[@qwertylim1307]

Shouldn't acidic oxides be non metal ? 1:15:17 Thank you!!

[@ChemLectures]

Yes, there is an error. The subsequent slide corrects this error.

[@calebkx556]

Hi I’ve been watching all of your vids up until this topic are they applicable for combined Chem??

[@ChemLectures]

Its done for pure chem, but combined chem is a subset of pure, so definitely applicable. but just more than the combined chem content

[@tashfeenzaman9929]

Sir do you know a good website or free sources where I can find worksheet on these chapters.

[@ChemLectures]

not at the moment though apologies.

[@ンサムハイ]

Why should non metal oxides dissolve in water to react and produce an acid ? Thanks for the amazing lectures ❤️❤️

[@ChemLectures]

In simple thermodynamics, there is sufficient energy from the water molecules binding to the particles of the non metal oxides to pull them apart.

[@usmanmirza897]

Sir in checkpoint 6 how yow get 6hcl

[@jackkenway7483]

Can you also do a series on biology i know many people(including me ) which need help for it.

[@ChemLectures]

Presently focused on chemistry. Not much spare time on hand for bio, though might be a possibility in the future

[@geromelin4446]

Hello sir may i ask for 14:50 why testing for acid is dry litmus ,shouldn't it be moist?

[@ChemLectures]

aqueous acids already contain water. only for gases does the litmus paper need to be moist to provide the water for the gas to dissolve in.

[@umairsafdar7494]

Thanks allot sir.. This helped me allot :)

[@ChemLectures]

+Umair Safdar welcome!

[@umairsafdar7494]

previously sir i used to have problems in solving the past papers questions but now this helped me allot.

[@ChemLectures]

+Umair Safdar great! any qns you need help with you can always pop them here or on the chem lectures facebook page facebook.com/chemlectures.SG/

[@laura-dr1yf]

hi, im confuse at the alkalis part where there is a precipitation reaction. how do you know which color which metal gives out?

[@ChemLectures]

colour of ppt for the moment you will need to remember them. Cu2+/Fe2+ 3+/Cr3+ are the more common metal ions. The rest of the metal ions are colourless in aqueous solutions

[@laura-dr1yf]

is it color of the common metal ions mentioned in any of the videos?

[@ChemLectures]

it will be in the video for qualitative analysis

[@pixpixpix394]

1:31:33 isnt CaSo4 insoluble? why do we put the aqueous sign?

[@ChemLectures]

its sparingly soluble. at low concentrations, it is soluble, at higher concentrations, it is insoluble

[@pixpixpix394]

thankyou! ❤

[@AlexisXen]

I was taught that all Group 1 metals and ammonium compounds are soluble. Is that considered right?

[@ChemLectures]

+Noelle Alanis yes this is right

[@thekawaiistyle4]

hi sir. to clarify, can copper react with metals? because i was taught that copper is a unreactive metal

[@thekawaiistyle4]

sorry can copper react with acids*

[@ChemLectures]

nope. not with dilute acids.

[@myerali9536]

Thank YOU So much greatly appreciate your efforts for covering the entire O level Syllabus of Chemistry i wanted to ask about alternative to practicals of O level chemistry which include topics like titration .test of ions etc how shall i prepare for them -thanks in advance

[@ChemLectures]

+Myer ali check out the video on qualitative analysis. This one is on test for ions. For titration, it is under preparation of salts. As for how you can prepare, it really boils down to hands on, so you will need to ask your teacher for additional lessons.

[@anaruskral5583]

Hi Thank you sir, how can I get the notes plz

[@anaruskral5583]

İ found it Plz accept my request ☺️

[@kzdwt9969]

wait why is ammonium sulfate acidic how do we know?

[@ChemLectures]

don't need to know for GCE O levels. But yes, it's acidic because NH4+ can react with water to give H3O+ ions.

[@talhaalraicoalix6886]

SIR, in an ionic equation if there's aqueous Ammonia present {NH3(aq)}, will it dissosciate into ions and what ions?

[@ChemLectures]

Yes, it undergoes the following reaction: NH3 + H2O --> NH4+ + OH- So you get ammonium ion and the hydroxide ion. You will need to write this equation first, before you proceed to write the rest of the ionic equations

[@derjemand1021]

Sir isn't ammonium chloride soluble in water? But at 48:00, we can see that u wrote 2NH4Cl(s).

[@ChemLectures]

Yes it is. But just that i'm thinking along the lines of adding powdered ammonium chloride to an aqueous solution. YOu can use aq as well, doesn't really impact anything here.

[@daudsardarrr]

Why H2O is added To aqueous NH3 ? Cant we proceed the reaction with Aqueous NH3 since water is already present

[@ChemLectures]

this is a way of showing the chemical reaction that NH3 undergoes when it is placed in water. Because to form the OH- ion, NH3 must first react with H2O.

[@ciarasu]

what do you mean when you say that amphoteric oxides are metallic oxides? does that mean that they are oxides of metals like basic oxides? what classifies as an metallic oxide?

[@ChemLectures]

metallic oxides are oxides containing metal elements, e.g., Na2O. Al2O3. Na and Al are metals. Non metal oxides are oxides containing non metals, e.g., CO2, SO2. C and S are non metals

[@ciarasu]

Chem Lectures thanks!

[@realdefalt4923]

Excuse me sir but isn't Calcium sulfate, CaSO4 insoluble? So how come in checkpoint 7 Q1.c you wrote it as aqueous? Explanation would be very appreciated. Thanks in advance.

[@ChemLectures]

hmm, there's no calcium sulfate mentioned. are you referring to calcium hydroxide?

[@realdefalt4923]

Chem Lectures In the products side it is calcium sulfate but you wrote it as aqueous instead of solid which confused me.

[@michaelonyekachinkulo62]

This is very nice. Is it possible to get all the notes?

[@ChemLectures]

+Mike Michael sure. go to www.chemlectures.sg to register an account. do pass on the info to your friends

[@Ali-mi9up]

In the reaction between calcium hydroxide and dilute sulfuric acid , calcium sulfate is produced.How come it forms ions? Isn't it insoluble ?

[@ChemLectures]

Muhammad Ali calcium sulfate is sparingly soluble. in very low concentrations it will appear to form a colourless solution. at higher concentrations, the undissolved calcium sulfate will precipitate out

[@ibraheembaloch9772]

how to distinguish between h2so4 and hcl

[@ChemLectures]

add aqueous barium nitrate. BaSO4 -> insoluble white ppt. BaCl2 -> soluble

[@weeteck223]

calcium hydroxide is fully soluble or sparingly soluble?

[@ChemLectures]

+Momo Tan its sparingly soluble. when a little of it is dissolved completely in water, you get limewater, the chemical used to detect carbon dioxide through the formation of white precipitate when carbon dioxide is bubbled through it.

[@javonlee5869]

Hi Sir, how do we tell if an oxide/hydroxide is soluble or not? Thanks

[@ChemLectures]

Oxide/hydrogen of Group I and II metals are soluble. As for the rest, follow the solubility table.

[@javonlee5869]

Noted thanks

[@ciarasu]

how do you know which bases are alkalis too?

[@ChemLectures]

bases which are soluble in water are alkalis. Go with the solubility table, e.g., all group I metal compounds are soluble in water, i.e., Na2O is a group I metal oxide. It is a basic oxide because it can react with acids, and it can dissolve in water to form hydroxide ions, i.e., Na2O dissolves in water to give NaOH.

[@legend9872]

Hello Mr. chua tung kian, please approve my request for the notes, thank you. Also really appreciate these videos, theres literally no other video resource for o level style chem preparation.

[@ChemLectures]

done

[@dakangee8221]

Thank you so much. This really helped me. Can you help me approve so I can have the notes?

[@dakangee8221]

Approve my request

[@ChemLectures]

+Dakang Ee done

[@AbdulRehman-im2wc]

SIR PLS APPROVE REQUEST FOR NOTES

[@ChemLectures]

already approved

[@microgamerz50]

nice

[@hibax631]

thankyou ! this video is really helpful I'd probably get an A grade in tomorrow's paper

[@ChemLectures]

all the best!

[@abbasali7050]

Sir, Any easy way to learn Valency of all Metals and Non-Metals ?

[@ChemLectures]

follow the periodic table. usually it is the group number for the 1st 20 elements

[@abbasali7050]

@@ChemLectures Oh okay Thank you sir, One More this I'll not be giving The Practical Paper(Paper3) I'll be giving Paper 4(Alternative to practical) so should i watch and learn Qualitative Analysis Topic ?

[@dbzhassan5331]

Hello, I want to appear for add maths in May 2016 o levels, plus I need help for maths too which I will appear for May 2016 too....please guide me if u have some notes on them

[@dbzhassan5331]

2017*

[@ChemLectures]

doing chemistry as focus now

[@dbzhassan5331]

Haha thanks tho

[@dbzhassan5331]

Unlike others is good to see u replying to everyone

[@ChemLectures]

I try to, though may be fast or slow depending on my current workload!

[@mariashabbir5810]

Can you do biology and physics pleeeeeez....before caies

[@osamashoaib1339]

Are all mineral acids strong acids?

[@ChemLectures]

+Osama Shoaib yes, almost all mineral acids are strong acids.

[@ciarasu]

hi this is prob a stupid qn but are acidic oxides and amphoteric oxides bases?

[@ChemLectures]

amphoteric oxides can react with both acids and alkalis. They can thus behave as a base.

[@ciarasu]

Chem Lectures thanks!

[@syedmuhammadmusakazmi3980]

I live in Pakistan, where will i get your notes from?

[@ChemLectures]

www.chemlectures.sg or www.chemistrylectures.com

[@mehreenayub6831]

Do you happen to be selling your notes?

[@ChemLectures]

mehreen ayub the notes are free. go to the associated website www.chemlectures.sg to download the full set. do introduce to your friends too!

[@mehreenayub6831]

That's great! Thanks! Yeap I sure will!

[@talhamostwanted1333]

reaction of calcium hydroxide and dilute sulfuric acid produce insoluble calcium sulphate which is aloso a precipitation reaction but you wrote it aqueous?? :/

[@ChemLectures]

Calcium sulfate is partially soluble. i think you may be confusing it with calcium carbonate, which is very insoluble.

[@faizanqaiser4027]

so nh3 is an alkaline gas but its compounds are acidic... how did that happen

[@ChemLectures]

+Faizan Qaiser I think you are misinterpreting something here. Nh3 is an alkaline gas, that is correct. When it reacts, it forms the ammonium ion. Eg nh3 + hno3 -> nh4no3. For example, ammonium nitrate. Nh4+ is acidic because it can react with water to give the hydroxonium ion, commonly known as the hydrogen ion that acids release. Nh4+ + h2o -> nh3 + h3o+. This gives the ammonium ion its acidic properties.

[@faizanqaiser4027]

+Chem Lectures (Chua Tung Kian) interesting dual properties...thanks

[@sumbalaroojkhan1786]

+Chem Lectures (Chua Tung Kian) how can I get ur notes? I want solved exercises n questions too

[@Kednama007]

Hi sir! Can you approve my application for the notes! Thanks alot for the great videos! :)

[@ChemLectures]

EdnaYippy done!

[@YourWorstNightmare475]

Sir i need notes plz give

[@ChemLectures]

www.chemlectures.sg

[@elvirastrauss4373]

I believe in God thanks to you.

[@ChemLectures]

glad you found the resources useful

[@AbdulRehman-im2wc]

SIR KINDLY ACCEPT MY REQUEST FOR UR NOTES

[@ChemLectures]

already accepted

[@zunairahmalik2148]

What is Basicity of an acid?

[@ChemLectures]

It's covered within the video. Look through and study it

[@manahilshafiq2925]

Zunairah Malik hi zunairah

[@osamashoaib1339]

can all acids conduct electricity

[@ChemLectures]

+Osama Shoaib if the acid can dissociate to form ions, then yes, it can conduct. This usually occurs in aqueous state (i.e., when the acid is dissolved in water). Very concentrated acids do not dissociate fully and are very poor conductors of electricity.

[@ummeaaliyan669]

Sir where is oxidising and non-oxidising acids?

[@ChemLectures]

not in the o level syllabus

[@ummeaaliyan669]

Sir it has been added. Please re-check. Humble thanks

[@trevenramasawmy7709]

dissociaton of hydrogen sulfide?

[@ChemLectures]

in relation to?

[@howto302]

ertgrul

[@ibraheembaloch9772]

is coppersulphate soluble

[@ChemLectures]

yes.

[@aaqibansari3666]

sorry I checked the notes and got answer

[@malaikanaeem7271]

Please approve my request, I have my chemistry CIE the next month. Thankyou :)

[@ChemLectures]

+Hamda Anjum done

[@malaikanaeem7271]

Thankyou. Your videos really helped :)

[@dominiclei4680]

31:16 fire alarm

[@howto302]

ergrul

[@htgadgets4151]

Sir plz approve my request for notes

[@tzgamer7136]

isn't water amphoteric

[@ChemLectures]

nope, it's neutral, pH 7

[@nursyafiqahmusyirahbtemusa5708]

hello sir,can you approve my application for the notes? :)

[@ChemLectures]

+nur syafiqah musyirah bte musa done

[@rachaelchua6420]

hi sir, could u pls approve my application for the notes? thx: )

[@ChemLectures]

+rachael chua should be done alr

[@heroman1596]

sir can you accept my request ? and can you please make lectures on Paper 4 of chemistry

[@ChemLectures]

+Hero Man done

[@heroman1596]

+Chem Lectures (Chua Tung Kian) sir. can you make lectures for alternative to practical chemistry

[@maryamsiddiqui2839]

Mr Chua I have sent you a login request for notes plz accept it as soon as possible because my mid year exams are coming and I want your notes

[@ChemLectures]

done

[@ChemLectures]

unless you have use a spoofed email acct

[@tehzeebshahbaz538]

Chem Lectures I have sent you a login requet . Please accept as soon as possible -thanks

[@chuaadelpheus9656]

be my teacher

[@kzdwt9969]

hii please accept my request for the lecture notes!! :) thank you sm

[@ChemLectures]

done!

[@shaheertaimuri2946]

sir plz accept my request on your website for lecture notes i hav paper october 2018 cie

[@ChemLectures]

should be done

[@shaheertaimuri2946]

@@ChemLectures thanks

[@aaqibansari3666]

is it free?

[@ChemLectures]

what is free? hmm..do clarify.

[@itbamalahat2226]

Sir, can you please accept my request on the website? Thank you

[@ChemLectures]

done

[@user-to6wd5gb8v]

Hi Sir ! Can u approve my application for the notes?

[@ChemLectures]

+WW Wong done!

[@ChemLectures]

go to www.chemlectures.sg or www.chemistrylectures.com for the notes and guides

[@ChemLectures]

***** go to www.chemlectures.sg or www.chemistrylectures.com for the notes and guides

[@osamashoaib1339]

sir please approve my request for the notes

[@ChemLectures]

+Osama Shoaib done!

[@osamashoaib1339]

+Chem Lectures (Chua Tung Kian) Thankyou sir they are very helpful

[@shravantoolsee]

+Chem Lectures (Chua Tung Kian) sir accept mine also please