GCSE Chemistry - What is a Limiting Reactant? Limiting/Excess Reactants Explained #27
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- Опубліковано 6 бер 2019
- Limiting and Excess Reactants Explained.
Often, in chemical reactions there will be less of one reactant that the other - we call this one the limiting reactant because how much reaction can take place. Whereas the more abundant reactant is in 'excess' because there is more of it than we need.
This video is suitable for:
- Higher tier only
- All exam boards
- Triple and combined science
Balancing Equations video:
• GCSE Chemistry - Balan...
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Amadeus & Tom
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!
Thanks Salma, so great to hear that
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.
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
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!!
i struggle with chemistry too :( but i’m so stressed that i don’t understand half of the stuff
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.😢
This man is single handedly saving my chemistry GCSE. Could not be more thankful!
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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!!
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
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
@@ibphysicsclassroom bruh not every teacher can teach well
@@IHatemypastfr I’m doing all of the whole spec again for all topics
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!
This is a clear and coherent explanation. It is phenomenal!
Really helped me to understand this topic a lot better:)
Idk why this video doesn't have more views, it was so useful! Thank you, just subscribed :)
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
thank you so much for this! I had missed a lesson and had no idea what was going and this helped me greatly!
UA-cam teaches me more in 5 minutes than my teacher in a few months. Thank you so much ✨
thank you Jesus for these videos saved my life
He says you’re welcome 🤙
Thank you! This helped me to really understand the topic more!
Helping me when ny science teacher won't, this is a life saver ❤
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!
Thank you so much, very good explanation, I finally understand
That’s great to hear! Thanks 🙌
Thanks for explaining this in easy way i finally understand 🥰
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.
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.
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.
We are confused about the same thing, thank goodness it’s not just me. 😅
I'm just falling this. I just dont understand
Same
You are also failing English class. It’s failing not falling
@@ShahdAl-Ali 🤣🤣🤣🤣🤣
Fr
😭😭🥄@@ShahdAl-Ali
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.
Hope your assessment goes well James 🤞
This video is so useful. It helped me very much to get through limiting reactants
Ah thanks Khansa, so glad it helped! 👍
This was sooooo useful!
thank you for the very useful video
very helpful thank you so much! Please make a video or put a link on how to solve for stoichiomery
Thank you
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!!!
now that my schools science departments terrible, i genuinely feel like telling them to use cognito over teachers and save the money
Thank you so much. Are all your videos for students doing higher tier?
Now I finally get this topic by reading the description lol
Thank you 👍
Hello Mr Cognito! At 3:22 you multiplied 5 by 2 is the 2 Na or 2Na20 < the original one.
I love this Cognito❤
only helpful video i found on the topic
Thanks Hasan - really appreciate the comment!! Great to hear it was useful, and comments help the videos get seen which is great for us 🥳
Thx! Great vid.
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?
Cognito yep sorry. Misunderstood. It is correct
@@BobMarley-yz4wh No worries at all - we definitely want to know if something's wrong so we can fix it!
thanks maaaan
Thanks a lot!
You’re welcome!
bless you
is the cation always the limiting reactant?
this is god sent even tho my exams are cancelled
Suryan Nair no
at 3:12 , why is the ratio for sodium 2:1 when sodium on both sides are 4? shouldn't it be 1:1 ?
@@starlesscitiess thank you so much this helped a lot :)
Thanks for helping 🤌🏻
Thanks
does anyone know how he got 5 for moles in the question. i cant figure it out
Confused me to, I thought it would be 4 moles.
@@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!
Thanks bc im a reporter of this topic in my ps class
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 :)
Thanks Erika, glad we could help 👍
By any chance were you an IB student
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;
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).
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
I dont know either could you help??
I’m confused about the same thing.
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.
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
Hi, do you know why it is important to have excess of one of the reactants?
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 :)
@@abishasivakumar9001 ahhh right okay, that does make sense. Thankyou!!
Why Na+O2 can't give NaO rather than Na2O
He iş the goat
Exams in less than 3 week. Hope you ready
Mocks tomorrow ay ay ay
At 2:31 why its not 2Na at the reacrant side and just Na²O as product?
How did you make that tiny 2 and O?
How do you get the 4Na+O2
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!
fooken legendddd
at 3:02 shouldn't you have multiplied 23 by 4?
i was thinking the same thing oof
😭 me to. Now I have to turn to my thick accent science teacher who makes it complicated.
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.
put this in 2x speed with Low by Flo Rida on in the back and make notes at God speed
wautah
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. 😫🤯😱
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).
you are a legend, i was so lost and forgot the basics of chemistry
who the fuc are you thinking u r u btch asssholeee
Dumb question but why is na+o2 not nao2?
@@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