(15th of 19 Chapters) Energy Changes - GCE O Level Chemistry Lecture

(www.chemlectures.sg) GCE O Level Chemistry Lecture Series: Get your Distinction in Chemistry. No frills, no flashy stuff, just 100% coverage of the O Level Chemistry syllabus for the GCE O Level examinations

[@wardanaeem2227]

I like your videos I am from Pakistan . can you make another video separately for Haber's process and contact process

[@ChemLectures]

+Warda Naeem Hi, haber process is under ammonia video. contact process has been removed from the gce o lvl syllabus, hence there are no videos for it here.

[@hasnainshaikh3383]

@@ChemLectures but according to the latest syllabus , contact process is in the syllabus

[@ussaidishaq5091]

These are probably the best O levels subject videos online. Thank you so much!

[@ChemLectures]

glad you found they helped. let your peers know too!

[@themarschievous]

Majority of Pakistani students come for help to his amazing videos lol , Im Paki too and tbh I understand him more than my own teacher!

[@magmamusic4543]

Wow such a great and long lecture.love it .hope to gain same feelings from the next lecture

[@FurorInverse]

Extremely helpfull..... im passing my o levels just by your help,,,, thanksss sir

[@iftikharahmed4270]

a way to remember the energy profile diagram is to assume the energy profile diagram of an exo reaction is kinda like a z btw good luck with the exams yall

[@cindyboateng4735]

I am really enjoying the lecture . Thanks to it, chemistry is my favourite subject

[@ChemLectures]

Glad to hear that

[@cashingmadness4680]

HAIYAK PIAK at 14.33 :O Thank you so much Mr Chua ^-^

[@ace6929]

Thank you for making these vidss, def aiding me with my finals, and eventually o'levels

[@muhammadhuzaifa6705]

Thanks won't be enough for the work u have done. Your lectures are very helpful.GOD BLESS YOU

[@ChemLectures]

welcome. do let your friends know if you think the videos have helped

[@muhammadhuzaifa6705]

i'll

[@zehrajafri867]

Sir you are awesome my prayers are with you always you are doing a great job. you helped me alot through these videos and you actually made me love chemistry before watching your lectures I feel like chemistry is the toughest subject but the way you explain everything is awe inspiring and I am in love with chemistry now..

[@ChemLectures]

welcome.

[@shahwarakbar8836]

Your videod have been really helpful. Love from Pakistan

[@madeleinewang5052]

Awesome videos you have made! thanks a lot!

[@eshahashmi300]

Your videos are the best. Thank you so much!!

[@ChemLectures]

Glad you like them!

[@manahilshafiq2925]

Hello sir You stated in your video that we will observe increase in temperature in an exothermic reaction and we will see decreases temperature in an endothermic reaction. So is this change observed in the surrounding or in the solution/reactants?

[@ChemLectures]

it is change in the surroundings. when you touch an exothermic reaction mixture for example, your hand feels hot. You are the surrounding and heat is transferred to you.

[@eishaf2011]

Thank you sir it helped me alot😊

[@ChemLectures]

glad you found them useful

[@muhammadinamulhaq5786]

At <a href="#" class="seekto" data-time="2646">44:6</a>6, when its ask at which electrode does oxidation takes place. Can we say at anode because (hydrogen gains oxygen to form water)

[@ChemLectures]

You can't say hydrogen gains oxygen to form water because it doesn't gain oxygen. Follow the explanation in the video. That would be most accurate.

[@farzanamalik4032]

Thank you these videos helped me alot but I have a doubt that is in the Q where they asked us about energy required to break methane shouldn't it be equal to C +4H=CH4 but my ans is nt coming equal itis coming CH4 =1648kJ and C+H=2092

[@ramshaazhar2195]

Your videos are amazing!!

[@ChemLectures]

Glad that they helped. Do let your friends know if you found them useful too.

[@shawanazaheer1420]

your videos are a great help to me so thank u a lott sir and can u please add a video for contact process (sulfuric acid)? because it is included in the GCE syllabus

[@ChemLectures]

hello. i have not included this as it is not in the Singapore GCE syllabus. but yes, can look into including this in the near future.

[@darkpurple3283]

Which statement is correct for an exothermic reaction: (a)the temperature of the substances falls or (b) the temperature of the substances rises. Any idea? I chose (a) because the substances reacting give out energy....thanks!

[@ChemLectures]

+Dark Purple (a). the temp of the surrounding rises because the temp of the reacting substances increases. simple analogy, if you touch a piece of burning paper, the heat from the paper will burn you.

[@wanderwonder20]

R u from Singapore..I really admire u..plz can I opportunity to visit Singapore n study there...

[@hassaankhan6774]

At <a href="#" class="seekto" data-time="2824">47:04</a> , why the energy profile diagram does not have activation energy curve ?

[@ChemLectures]

i see what you mean. You can add it in for this question to show the curve.

[@yahyanaveed3686]

Do your notes cover the GCSE O-LEVEL syllabus for places such a Pakistan

[@ChemLectures]

yes, it covers beyond GCSE o level. the GCE o lvls for Singapore is one of the most rigorous O lvls in the world. And I have several students from Pakistan who have emailed/messaged me to say they received their distinctions/A's from watching the videos and going through the notes

[@wanderwonder20]

Chem Lectures where can I get ur notes from

[@ZahabzMedic]

Good stuff

[@wardanaeem2227]

Thankyou

[@ahmedahmedarshad7817]

Chem lectures can you please tell in which video you have explained electrolysis??

[@ChemLectures]

There is a video specifically titled electrolysis

[@waniasiddique9346]

Do we only use KOH as electrolyte in fuel cell or can we use any other substance??

[@ChemLectures]

Preferably KOH.

[@faizanqaiser4027]

there is one concept that is not present in ur videos... if in a reversible reaction the forward reaction is exo/endothermic what happens to the rate of forward reaction when i in/decrease the temp. i understand how it works but i need a cie compatible answer... thanks

[@ChemLectures]

+Faizan Qaiser Hi there, this is not in the O level syllabus, hence it is not included in the videos. you would probably know the simple explanation already (from what you have said). a CIE compatible answer would be something like this:Le Chatelier's principle states that a reaction in equilibrium if disturbed by a change in condition will change the position of the equilibrium to remove the disturbance. For an exothermic reaction, when the temperature is increased, the rate of the forward reaction decreases to reduce the heat energy evolved during the reaction. Correspondingly, the rate of the backward reaction increases, to remove the excess heat from the reaction system.

[@faizanqaiser4027]

+Chem Lectures (Chua Tung Kian) thanks u really care about ur viewers

[@ChemLectures]

+Faizan Qaiser welcome!

[@fauzianaeem3300]

Sir, I have signed in for your notes and lecture page several times but still i did not get that approval mail?

[@ChemLectures]

try to access the notes with your registered email

[@amirmumtaz3119]

How can I get your notes

[@ChemLectures]

www.chemistrylectures.com

[@sapphirewillow5304]

Hi sir, at <a href="#" class="seekto" data-time="2864">47:44</a> why is the equation H2 + halfO2 -->H2O ? Can it be 2H2 + O2 --> 2H2O ?

[@ChemLectures]

sure. it can be. it's just the way of balancing. doesn't really matter. so long as both sides have equal number of atoms of each kind.

[@sapphirewillow5304]

ok thank you

[@waniasiddique9346]

Do we have to learn bonds energy or they are given in paper??

[@ChemLectures]

values will be given.

[@waniasiddique9346]

Chem Lectures Thanks sir

[@wassamahmedkhan5378]

dear sir i want your notes

[@madman007rockZ]

Thx bro

[@ChemLectures]

welcome

[@matendewilsonpaul603]

CAN IN HELP IN UGANDAN SCHOOLS WHERE I TEACH??

[@ChemLectures]

depends on what the syllabus is?

[@RimsandwheeksUK]

Hi my name is Taimur Kiani . I like your videos can you give tips yo get good grades in o level Chemistry

[@ChemLectures]

read and understand the notes, and practice the questions.