I love all your videos so much, without them I would be failing chemistry. My teacher can not teach at all so your videos are my only source of explanations
This is such a great video! I missed a few classes of this topic and always avoided it in revision but you’ve made it so so clear. I’m really thankful, hopefully I can smash my exam 🥰
Yeah I noticed that. The MgO born Hager cycle is shown on page 25 of the CGP revision guide if you need it. Although it’s also a bit misleading because it doesn’t show an upwards arrow for second electron affinity of oxygen. Other than that it’s fine.
Hi, thanks for these videos - they're super helpful. you mention at around 21:35 a way you check your answers where you start at any point and get 0 as an answer. can you elaborate or maybe give an example? I keep checking but im not getting zero. thank you :)
Yes, if you put all the numbers in the cycle and go round the cycle (remember when you go with the arrow you keep the sign the same, when you go against the arrow you change the sign). The numbers should add up to zero.
Thank you so much, these videos are helping my understanding of chemistry vastly. I'd like to point out a small error at 25:33, where I think, the ionic compound on the bottom line should be MgO rather than LiCl?
No because the value of 242 is for Cl2, but in the equation you only have Cl, so you need to divide the original atomisation number to get the value for only on Cl atom instead of Cl2, if that makes any sense 💕
@@victoriaovenseri8054 pretty sure you are incorrect, atomisation is when you form one mole of gaseous atom from its element in its standard state, we form one mole of Cl of gaseous atom so its it is ONE ATOMISATION ENERGY
@@joshuaroney but if you calculate the bond enthalpy for Cl2, you produce TWO moles of Cl, we only need one mole of Cl, so half of a Cl2 molecule is used, so half the bond enthalpy
@@joshuaroney from its element in its standard states, therefore it needs to be Cl2 as chlorine is diatomic in its standard state. Therefore it is 121.
I'm a bit confused. At 31:00 when you talk about the experimental v theoretical enthalpies you say that the experimental value is higher, but as they are negative numbers surely -845 is higher than -852?
The negative sign is just there to show it is an exothermic reaction (and conversely a positive sign is used for endothermic values). Ignoring the sign, the experimental values are always greater (ie bigger number) than theoretical values. This is because theoretical values are based on pure ionic model ie does NOT take into account that covalent character is also present. This is referred to as polarisation - which is greater for highly charged ions (eg +2/-2 ions) and also larger anions( eg I- higher than Cl- as larger electron cloud is more easily distorted by adjacent positive ion). Hope that helps!
The government should give grants for this , has helped me and thousands of others. Thank you for what you do and don't stop !
No problem, thanks for your kind words 😊
I love all your videos so much, without them I would be failing chemistry. My teacher can not teach at all so your videos are my only source of explanations
Couldn't get my head around this topic for ages and this video finally helped me to understand, thank you!
You're very welcome 😀
Thank you so much for all the work you do, we all appreciate you so much! 👩🏻🔬
You are so welcome
i’ve been watching these for 2 years and seen every comment as everyone panicking about they’re exam tomorrow mines coming up but wow
Thank you so much your videos are saving me so much time so i can spend it more on practice questions rather than just learning the content
This is such a great video! I missed a few classes of this topic and always avoided it in revision but you’ve made it so so clear. I’m really thankful, hopefully I can smash my exam 🥰
You're welcome! Hope your exam goes well. 👍
day before the exam and just started my revision gang where we at
🙋♂️
preachhh
Right here, just glanced at the advanced info, starting from the top down :P
@@etragun exact same here skipped the transition metal 1 though finna fall asleep watching it
how did you do?
you my friend are preventing me from failing
your videos just make it so easy and clear for *understanding* !! thankyou so much.
These videos are so clear and my favourite for revision - thank you!
very concise and informative video. cheers sir.
Glad you liked it
At 4:08 wouldn't the equation for the formation of ethane require 3 lots of H2 rather than 2?
Thank you Allery chemistry !!!
Thank you I find this to be very helpful, it is clear and concise.
Glad it was helpful! 🙂
great summary videos! please can you do videos for aqa required practicals
With regards to the born haber cycle of MgO. Why is O2. Shouldn't it be half O2 because only one oxygen is being used.
Yeah that whole slide was wrong. Google ‘MgO Born Haber cycle’ and it comes up
Yeah I noticed that. The MgO born Hager cycle is shown on page 25 of the CGP revision guide if you need it. Although it’s also a bit misleading because it doesn’t show an upwards arrow for second electron affinity of oxygen. Other than that it’s fine.
A level chem 2022 let me hear your voices! (The night before the exam as well lol)
how did it go
Is there a playlist for AQA Year 1 Chemistry?
Hi, thanks for these videos - they're super helpful. you mention at around 21:35 a way you check your answers where you start at any point and get 0 as an answer. can you elaborate or maybe give an example? I keep checking but im not getting zero. thank you :)
Yes, if you put all the numbers in the cycle and go round the cycle (remember when you go with the arrow you keep the sign the same, when you go against the arrow you change the sign). The numbers should add up to zero.
@@AlleryChemistry got it now, thanks!
These videos really help, thank you
Happy to help!
Thank you so much for this video. Very helpful.
You are so welcome!
I'm pretty sure delta G (Gibbs free energy change) is measured in KJ/mol
Thank you so much, these videos are helping my understanding of chemistry vastly. I'd like to point out a small error at 25:33, where I think, the ionic compound on the bottom line should be MgO rather than LiCl?
He does mention this 24:45
16:33 isn't the value of atomisation of chlorine wrong here, as one mole of Cl is being formed, meaning it should be 242 instead?
No because the value of 242 is for Cl2, but in the equation you only have Cl, so you need to divide the original atomisation number to get the value for only on Cl atom instead of Cl2, if that makes any sense 💕
yeah i am pretty sure that part is wrong
@@victoriaovenseri8054 pretty sure you are incorrect, atomisation is when you form one mole of gaseous atom from its element in its standard state, we form one mole of Cl of gaseous atom so its it is ONE ATOMISATION ENERGY
@@joshuaroney but if you calculate the bond enthalpy for Cl2, you produce TWO moles of Cl, we only need one mole of Cl, so half of a Cl2 molecule is used, so half the bond enthalpy
@@joshuaroney from its element in its standard states, therefore it needs to be Cl2 as chlorine is diatomic in its standard state. Therefore it is 121.
51:50 delta H is measured in kjmol not jmol
Not in Gibbs Free Energy calculations, he highlights that you have to convert to Jmol-1.
I'm a bit confused. At 31:00 when you talk about the experimental v theoretical enthalpies you say that the experimental value is higher, but as they are negative numbers surely -845 is higher than -852?
The negative sign is just there to show it is an exothermic reaction (and conversely a positive sign is used for endothermic values). Ignoring the sign, the experimental values are always greater (ie bigger number) than theoretical values. This is because theoretical values are based on pure ionic model ie does NOT take into account that covalent character is also present. This is referred to as polarisation - which is greater for highly charged ions (eg +2/-2 ions) and also larger anions( eg I- higher than Cl- as larger electron cloud is more easily distorted by adjacent positive ion). Hope that helps!
@@ajtrott1 this is really helpful thanks
Thank you!
You're welcome!
At 26:27 when the arrow goes down, why has 2O changed into just O? Where did the second oxygen go?
I think at some point it should have been 1/2O2 and not 2O
Thank you so much!
You're welcome!
Thank you
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I’m in love with u
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The magnesium born harber is wrong its meant to be 1/2 02
Cheers
40:00
thank you, I love you, Jesus loves you too im sure. xxxxxx
is it just my screen not focusing or is the video really blurry?
I think it's just your screen
@@puddleduck1405 Yeah, it's really clear for me
Click the settings in the top right corner and try change the quality of the video and click on highest (hp) this should help
😢
There is a mistake at 4:27 it should be 2C (s) + 3H₂ (g) -> C₂H₆ (g) and not 2H₂
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