If you’d like to practise the material covered in this video, check out our platform at www.cognitoedu.org - it's totally free, and has been built to make learning and revision as easy as possible. The main features are: - Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown. - Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on. - Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like. - A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts. - A comprehensive bank of past exam papers, organised both by year, and also by topic. Amadeus & Tom

@LevelUP84

5 ай бұрын

I’m a little confused, in the 2Na(small 2)O equation, how comes you only add 2 x 23 and not 2 x 46 as you balanced out the equation by adding the 2 in front so I thought it would be 2 x the 2 and not the 1 if that makes sense? 🤪 I’m new to this. Thanks.

This channel is single-handedly helping me get through Sciences and Maths especially in uncertain Covid times. Thank you so so much for all your hard work!

@Cognitoedu

3 жыл бұрын

Thanks Salma, so great to hear that

@mohamedking6297

Жыл бұрын

Are you somali salma

I kid you not I absorbed more information about limiting reactants in this 4 minute masterpiece of a video than I did in an entire year of chemistry lessons. Cheers.

I can’t believe it, I’m watching this video one last time before my exam tomorrow. And then I’m never gonna study chemistry in my life again.😢

thank you so much this has really helped me to understand this for my mocks. I struggle very much with chemistry and really appreciate good gcse videos

@Cognitoedu

4 жыл бұрын

Hi Maya thank you so much for taking the time to leave us a comment and let us know the videos are useful to you (it really helps the channel to grow/get seen) - we really appreciate it! Good luck with all your work!!

@xfreja

2 жыл бұрын

i struggle with chemistry too :( but i’m so stressed that i don’t understand half of the stuff

This man is single handedly saving my chemistry GCSE. Could not be more thankful!

@Cognitoedu

3 жыл бұрын

🤩🤩

i genuinely still cant belive how u can make me understand stuff in 5 mins which would take hours for me to understand in school

@ibphysicsclassroom

5 ай бұрын

Cos you genuinely don’t pay attention in class but here you take responsibility of your own learning. Those who did in class understood it

@IHatemypast

3 ай бұрын

@@ibphysicsclassroom bruh not every teacher can teach well

@garethbale2927

2 ай бұрын

@@IHatemypastfr I’m doing all of the whole spec again for all topics

this the best channel for gcse videos have seen so far. really appreciate your efforts these have really helped me with a lot of concepts for all sublets for that matter. hats off to the team!!

Thank you so much for all your videos. They help me in all the sciences so much! My mocks are this week and this has helped me to succeed so much!

KZread teaches me more in 5 minutes than my teacher in a few months. Thank you so much ✨

This is a clear and coherent explanation. It is phenomenal! Really helped me to understand this topic a lot better:)

thank you so much for this! I had missed a lesson and had no idea what was going and this helped me greatly!

Thank you so much this video was so helpful! The limiting reagent is the one topic that kept me stuck with stoichemistry but this allievated the burden!

Helping me when ny science teacher won't, this is a life saver ❤

thank you Jesus for these videos saved my life

@Cognitoedu

4 жыл бұрын

He says you’re welcome 🤙

Thank you! This helped me to really understand the topic more!

Idk why this video doesn't have more views, it was so useful! Thank you, just subscribed :)

@mubeenkouser7695

3 жыл бұрын

Even I don't understand seriously and I am so glad that I have found this on perfect time awesome video I literally wrote each and every thing you said in the video

I just want to say thank. I am taking my final assessment for science today and I want to say thank you for helping me through the stressful process of exams.

@Cognitoedu

3 жыл бұрын

Hope your assessment goes well James 🤞

Thanks for explaining this in easy way i finally understand 🥰

Thank you so much, very good explanation, I finally understand

@Cognitoedu

4 жыл бұрын

That’s great to hear! Thanks 🙌

very helpful thank you so much! Please make a video or put a link on how to solve for stoichiomery

hi, when you find the mr of na2 surely you do Na * 2 but whenin the video u did 2Na2 surely you have to times it by 4 a bit confused.

@lukebrice2040

2 жыл бұрын

Although it is of no relevance to you now, you do not need to multiply the Mr by the coefficient(2) at the front of the element.

@subbhy3791

2 жыл бұрын

You could do that and then you don’t need to do the molar ratio of 2:1. It will give you the same answer regardless.

@LevelUP84

5 ай бұрын

We are confused about the same thing, thank goodness it’s not just me. 😅

Thank you so much. Are all your videos for students doing higher tier?

This video is so useful. It helped me very much to get through limiting reactants

@Cognitoedu

3 жыл бұрын

Ah thanks Khansa, so glad it helped! 👍

Hi, regarding limiting reactants, will that change how we calculate the mass? Because at 4:02, you calculated the mass, as if there was no limiting reactant (does this limiting reactant really matter, and if so, when would it effect the equation) Thank you very much!!!

Hello Mr Cognito! At 3:22 you multiplied 5 by 2 is the 2 Na or 2Na20 < the original one.

is the cation always the limiting reactant?

I'm just falling this. I just dont understand

@TasneemPrangon

4 ай бұрын

Same

@ShahdAl-Ali

3 ай бұрын

You are also failing English class. It’s failing not falling

@sanmeetkapoor5748

3 ай бұрын

@@ShahdAl-Ali 🤣🤣🤣🤣🤣

@eshal3210

2 ай бұрын

Fr

@tealisbored

2 ай бұрын

😭😭🥄​@@ShahdAl-Ali

This was sooooo useful!

Sir how did u find 2.5 of NaO

now that my schools science departments terrible, i genuinely feel like telling them to use cognito over teachers and save the money

Now I finally get this topic by reading the description lol

thank you for the very useful video

thank you very much you saved me😇😇

Why Na+O2 can't give NaO rather than Na2O

at 3:12 , why is the ratio for sodium 2:1 when sodium on both sides are 4? shouldn't it be 1:1 ?

@nawal8790

3 жыл бұрын

@@starlesscitiess thank you so much this helped a lot :)

I love this Cognito❤

Thank you

how.. how did yk its Na2O when Na nd O2 react? like howd yk we'd need 2 sodiums? is there a video for this im lost D;

@galefray

Жыл бұрын

Alkali metals reacting with O2 can either give either Metal Oxide, Metal Peroxide or Metal Superoxide. You should remember that from video #11. Recap: Sodium Oxide = Na2O Sodium Peroxide = Na2O2 (A good way to remember perodixde is that it semantically tells you what it is, sodium PER oxide so... yeah lol. Overall things to rememeber from Video #11: All Alkali metals can react with Oxygen, Water or Chlorine. When reacting with Water: Metal Hydroxide + Hydrogen [Li + H2 ----> LiOH + H2] ~~ When reacting with Oxygen: Lithium + Oxygen ----> Lithium Oxide Li + O2 ----> Li2O ~ Sodium + Oxygen ----> Sodium Oxide Na + O2 ----> Na2O Sodium + Oxygen ----> Sodium Peroxide Na + O2 ----> Na2O2 ~ Potassium + Oxygen ----> Potassium Peroxide K + O2 ----> K2O2 Potassium + Oxygen ----> Potassium Superoxide K + O2 ----> KO2 ~~ When Reacting with Chlorine: Metal + Chlorine ----> Metal Chloride (Remember, Chlorine is a halogen all halogens become a halide when they react).

At 2:31 why its not 2Na at the reacrant side and just Na²O as product?

@LevelUP84

5 ай бұрын

How did you make that tiny 2 and O?

thanks maaaan

does anyone know how he got 5 for moles in the question. i cant figure it out

@LevelUP84

5 ай бұрын

Confused me to, I thought it would be 4 moles.

@zilovesmaths

4 ай бұрын

@@LevelUP84 He used the formula Moles = Mass / Mr The mass of the sodium is given in the question ('when 115g of sodium is burned in air') So we know 115g is the mass On the periodic table, the relative atomic mass of sodium is 23 So now using the formula moles = mass / mr moles = 115 / 23 = 5 So 5 moles Hope this helps!

Thank you 👍

Thanks bc im a reporter of this topic in my ps class

I’m a little confused, in the 2Na(small 2)O equation, how comes you only add 2 x 23 and not 2 x 46 as you balanced out the equation by adding the 2 in front so I thought it would be 2 x the 2 and not the 1 if that makes sense? 🤪 I’m new to this. Thanks.

@crxnge4483

4 ай бұрын

yeah i think its because the rfm is only the sum of the atomic masses of the atoms and that is not including the number of molecules

this is god sent even tho my exams are cancelled

@EcoHotdog

4 жыл бұрын

Suryan Nair no

only helpful video i found on the topic

@Cognitoedu

4 жыл бұрын

Thanks Hasan - really appreciate the comment!! Great to hear it was useful, and comments help the videos get seen which is great for us 🥳

How do you get the 4Na+O2

@zilovesmaths

4 ай бұрын

You need to balance the equation, as there need to be an equal amount of reactants and products on each side He's linked his video of balancing equations in the description so watch that!

Thanks for helping 🤌🏻

Hi, do you know why it is important to have excess of one of the reactants?

@abishasivakumar9001

3 жыл бұрын

it's not important to have an excess of one of the reactants, It is important that you know that one of the reactants is a limiting reactant and that means the other reactants are in excess, hope that makes sense :)

@graceabigail331

3 жыл бұрын

@@abishasivakumar9001 ahhh right okay, that does make sense. Thankyou!!

bless you

I have a chemistry paper 1 mock tomorrow and I am watching binge watching all the relevant videos ! They are SO helpful ! Thank you, you have saved me :)

@Cognitoedu

3 жыл бұрын

Thanks Erika, glad we could help 👍

@mohamedking6297

Жыл бұрын

By any chance were you an IB student

Thanks a lot!

@Cognitoedu

2 жыл бұрын

You’re welcome!

For the last example, why don’t you multiply the mr of the product by 2 Cuz there is a big 2 on the left of it? I thought that just means multiply the whole product by 2

@Aahir.

Жыл бұрын

I dont know either could you help??

@LevelUP84

5 ай бұрын

I’m confused about the same thing.

Thx! Great vid.

@Cognitoedu

5 жыл бұрын

Hi Abdul, thanks for the comment! We’ve double checked and we’ve done it for 115g which is exactly 5 moles of sodium. So it would produce 2.5 moles of sodium oxide which would have a mass of 155g. Have we understood you correctly, or is there something else you think we’re missing?

@BobMarley-yz4wh

5 жыл бұрын

Cognito yep sorry. Misunderstood. It is correct

@Cognitoedu

5 жыл бұрын

@@BobMarley-yz4wh No worries at all - we definitely want to know if something's wrong so we can fix it!

Thanks

He iş the goat

@arusu6478

3 ай бұрын

Exams in less than 3 week. Hope you ready

Mocks tomorrow ay ay ay

at 3:02 shouldn't you have multiplied 23 by 4?

@khaif.3376

2 жыл бұрын

i was thinking the same thing oof

@LevelUP84

5 ай бұрын

😭 me to. Now I have to turn to my thick accent science teacher who makes it complicated.

@LevelUP84

5 ай бұрын

I thought it would be 4 x 23 because he put the big 2 in front of the equation. And 2 oxygens instead of 1.

Good and brilliant 🇸🇱🇸🇱🇸🇱🎤🎤🧠📚📖📚

I thought it would be 4 x 23 because he put the big 2 in front of the equation. And 2 oxygens instead of 1. 😫🤯😱

fooken legendddd

put this in 2x speed with Low by Flo Rida on in the back and make notes at God speed

wautah

For everyone wondering where the NA2O came from: Alkali metals reacting with O2 can either give either Metal Oxide, Metal Peroxide or Metal Superoxide. You should remember that from video #11. Recap: Sodium Oxide = Na2O Sodium Peroxide = Na2O2 (A good way to remember perodixde is that it semantically tells you what it is, sodium PER oxide so... yeah lol. Overall things to rememeber from Video #11: All Alkali metals can react with Oxygen, Water or Chlorine. When reacting with Water: Metal Hydroxide + Hydrogen [Li + H2 ----> LiOH + H2] ~~ When reacting with Oxygen: Lithium + Oxygen ----> Lithium Oxide Li + O2 ----> Li2O ~ Sodium + Oxygen ----> Sodium Oxide Na + O2 ----> Na2O Sodium + Oxygen ----> Sodium Peroxide Na + O2 ----> Na2O2 ~ Potassium + Oxygen ----> Potassium Peroxide K + O2 ----> K2O2 Potassium + Oxygen ----> Potassium Superoxide K + O2 ----> KO2 ~~ When Reacting with Chlorine: Metal + Chlorine ----> Metal Chloride (Remember, Chlorine is a halogen all halogens become a halide when they react).

@myboyfriendsbetterthanyou4082

Жыл бұрын

you are a legend, i was so lost and forgot the basics of chemistry

@f9iteeditz

Жыл бұрын

who the fuc are you thinking u r u btch asssholeee

@Urmomlol6969

Жыл бұрын

Dumb question but why is na+o2 not nao2?

@zilovesmaths

4 ай бұрын

@@Urmomlol6969 Probably not gonna be of any relevance to you now but The Na + O2 are reactants, they're just separate elements However, when they react then they become Na2O (on the right side of the arrow) So at the start it's Na + O2 because they are separate at that time, but then after they react then they become Na2O Hope this helps if you still need it! 😂

Mr matthew sent me here

What’s Mr