thank you so much for all you do Sir!!! I’m a bit squiffy with quantitative chemistry despite being in top set maths because the wording is always daunting. Now I understand it though. YOURE A G, THANK YOU SO MUCH!! :)
when my actual chem teacher was teaching us abt this, I lowkey thought she meant 'Avacado constant''... went home, I searched everywhere for what it was (isn't even mentioned In the revision guide they gave us -_-) Now i am like 2 weeks away from my exams to learn that it is Avagadro's constant 😏 thank you freesciencelessons man 🤠
when you find the number of atoms in 54 grams of water, I found the mass of water which is 18 and 56/18 is 3 meaning there is a total of 3 moles of waters in 56 grams. Doesnt that mean it will be 3H^2O so there will be a total of 6 atoms of Hydrogen and 3 atoms of oxygen in 56 grams meaning there will be 9 atoms.
56 g of water is 3 moles of water. One molecule of water has 3 atoms so 1 mole of water will have 3 x Avogadro's constant of atoms. 3 moles of water will have 9 x Avogadro's constant of atoms.
Magnesium has an atomic number of 12. Calculate the mean mass of an atom of magnesium. Quote your answer to 3 significant figures. • Avogadro constant = 6.022 × 1023 atoms per mole PLEASE ANSWER
Hi. 1 mole of magnesium has a mass of 24 g. This contains 6.022 x 10^23 atoms. So divide 24 by 6.022 x 10^23 and that will give you your answer. The atomic number of magnesium is not actually relevant to this question (you need the mass number which is 24).
Thanks a lot. Really started to click for me now but seemed really daunting at first. I find the 'particle' idea quite vague in Avogadro's constant. I get now that a molecule can be a particle, but an atom can't unless it's present in element form (since there are several atoms in a molecule). Can anyone point me to an exact definition of the particle? When I google, it says even just an electron can be a particle but that wouldn't make sense with Avogadro's constant, or maybe it would if you get the number of molecules or atoms then multiply by the number of electrons... If an electron is a particle, can you have one mole of electrons?
Anything very small can be called a particle, including electrons, atoms, molecules etc. And we can have a mole of anything. One mole of anything will be Avogadro's constant of that thing. For example, a mole of electrons will be 6.02 x 10^23 electrons. A mole of pencils will be 6.02 x 10^23 pencils. I hope that helps.
Molecules such as O2, H2, Cl2 etc have two atoms in each molecule (they're called diatomic). If you have one mole of molecules (ie 6.02 x 10^23 molecules) then you have two moles of atoms (ie 2 x 6.02 x 10^23 atoms).
Because we are calculating the number of atoms in 3 moles of water molecules. Each water molecule contains 3 atoms (2 x hydrogen and 1 x oxygen). So we need to multiply the number of molecules of water by 3 to find the number of atoms.
In the last stage of the last question, when you are finding out the number of atoms, from the previous answer of molecules, why do you multiply by three?
Wouldn't the answer to the last question be 5.418 x 10^*25* since you're multiplying it with 3 (with the invisible power of 1) ? Or is it the same as doing 6 x (avogadros constant) ??
There are no past papers for the new GCSE. The spec is different in a number of ways, so I'm remaking all of the videos. However, there is still a lot of useful content in the old videos.
No problem. You could take a look at Corbettmaths and Hegartymaths. They might have what you need. I don't teach maths so I'm not really sure how good they are.
How can I calculate this: 48g if Sulfur dioxide is provided. Calculate the number of moles of SO2. (I just saw your other video on this and calculated it to be 0.75? I don't know for sure if this is correct, because for some reason, avogadro's constant is given to me.) (Never mind sir. I think I figured out there is 4.515 x 10^23 molecules - but can you still check please?)
Where did I go wrong? SO2 = One sulfur (32 Ar) & Two Oxygens (16 + 16= 32) = 64 Mr. Number of moles is mass/Ar = 48/64 = 0.75. (0.75) x (6.02 x 10^23) gives us 4.515 x 10^23 molecules of Sulfur Dioxide. Or am I still wrong? If so, is it possible for you to show me a quick calculation for this?
In standard form, the first number must be between 1-10. So 6.02 x 10^23 is fine as the first number is between 1-10. However, if we multiply that by 3, we get 18.06 x 10^23. That's not allowed as the first number is greater than 10. So to correct for that, we increase the power by 10 instead, from 10^23 to 10^24. This gives us 1.806 x 10^24 as the correct answer.
Sorry, I didn't read your message carefully. I do apologise. I'm afraid that the 2016 papers are locked on the AQA website. Teachers can see them but we are not allowed to post links as they're used as mock exams. However, they are normally opened on AQA around a week before the exams, so as soon as they're available, I'll put the link up.
taking my exams in 2024, this might be the hardest topic i've seen but you explained it so concicesly and thank you so much!
My pleasure. I'm glad that you found the video useful.
I’ve literally never been taught this in school 😬🤦🏾♀️ I didn’t even know what avagrado constant was. Thank you so much !!!!🧖🏾♀️
eudssss same it’s not in the revision book either
@@staceybaker5176 it is
oh wait nvm i realised we all live in the uk bc it’s for gcse’s lmao😂
@regibus361 in the CPG Triple Higher books it is atleast
cuz it wasn't on ur exam board lmao
thank you so much for all you do Sir!!! I’m a bit squiffy with quantitative chemistry despite being in top set maths because the wording is always daunting. Now I understand it though. YOURE A G, THANK YOU SO MUCH!! :)
Laura Dances eric birling 😳😳😳
Lizzie Somerville 😂😂😂
Eric Birling reference 😂
omg I feel the exact same way!! literally top set maths but this chemistry wording gives me headaches
Without him
Chemistry will always be a problem
Thank you sir
Everithing in science would be a problem without him
YOU HAVE HONESTLY SAVED MY GCSES!!!
What did u end u getting
@@hamimakter740 i guess we'll never know
@@marceledeko6030 Damn.
@@hamonthunder2740 wbu u guys, im a yr11 ima do mine in a couple of weeks what did u get
@@marceledeko6030 wbu u guys, im a yr11 ima do mine in a couple of weeks what did u get
Without you i would fail science
Ridita noboni preach
when my actual chem teacher was teaching us abt this, I lowkey thought she meant 'Avacado constant''...
went home, I searched everywhere for what it was (isn't even mentioned In the revision guide they gave us -_-)
Now i am like 2 weeks away from my exams to learn that it is Avagadro's constant 😏
thank you freesciencelessons man 🤠
Lol I've got exams this morning and this guy is the only person that can safe me❤
Your concise and simple explanations make hard topics seem like a breeze thanks bro
There is magic in your teachings, this video helped me.
Literally writing my finals this morning
Someone can literally get science home schooled by your videos 😂
shutup m8 (your actually right hes the best)
Great video, thank you teacher :)
morning of chemistry exam lads
I'm actually using this to solidify some undersanding for A Level Physics. I did not think I'd see the day.
this is involved with a level physics?
Shaun making me understand chemistry😮
you are WONDERFUL.
when you find the number of atoms in 54 grams of water, I found the mass of water which is 18 and 56/18 is 3 meaning there is a total of 3 moles of waters in 56 grams. Doesnt that mean it will be 3H^2O so there will be a total of 6 atoms of Hydrogen and 3 atoms of oxygen in 56 grams meaning there will be 9 atoms.
56 g of water is 3 moles of water. One molecule of water has 3 atoms so 1 mole of water will have 3 x Avogadro's constant of atoms. 3 moles of water will have 9 x Avogadro's constant of atoms.
GREAT VIDEO, THIS IS REALLY HELPING MY GCSE COURSE, THANK YOU!!!!
Magnesium has an atomic number of 12.
Calculate the mean mass of an atom of magnesium.
Quote your answer to 3 significant figures.
• Avogadro constant = 6.022 × 1023 atoms per mole
PLEASE ANSWER
Hi. 1 mole of magnesium has a mass of 24 g. This contains 6.022 x 10^23 atoms. So divide 24 by 6.022 x 10^23 and that will give you your answer.
The atomic number of magnesium is not actually relevant to this question (you need the mass number which is 24).
@@Freesciencelessons but to find the mass wouldn't you multiply the Mr by the mol
i have my chemistry paper 1 tmr thank you for helping me revise :)
anyone else bingeing these videos to get through chemistry tomorrow?
you are much Better than my teacher.. really you are great
MR BRUFF OR FREE SCIENCE LESSONS?
Free science lessons easily
mr bruff’s videos are so long
17 may Have my exam this morning and i realised last night that I cant do this... thank you so much if it comes up😂
Just to clarify at 3:50 you multiply the constant by 2 because there are 2 molecules (calcium and oxygen)?
He multiplies it by 2 because there are 2 atoms in the calcium oxide molecule.
@@amadif1793 so then why did he do all those extra steps
What an absolute legend
revise throughout the year❌
revise 2 hours before the actual exam🟩
You can tell he likes teaching this topic :D Haha
Is this likely to come up in this year's GCSEs? I've never got taught this in school??
Maybe. Maybe not. You just gotta learn everything.
It depends if you are doing foundation or higher because if you are doing foundation you don't need to learn this
My saviour
Exam tomorrow binge watching myman😔
omg your video saved me in ib
Thank you so much for this! ;)
Thanks a lot. Really started to click for me now but seemed really daunting at first. I find the 'particle' idea quite vague in Avogadro's constant. I get now that a molecule can be a particle, but an atom can't unless it's present in element form (since there are several atoms in a molecule). Can anyone point me to an exact definition of the particle? When I google, it says even just an electron can be a particle but that wouldn't make sense with Avogadro's constant, or maybe it would if you get the number of molecules or atoms then multiply by the number of electrons... If an electron is a particle, can you have one mole of electrons?
Anything very small can be called a particle, including electrons, atoms, molecules etc. And we can have a mole of anything. One mole of anything will be Avogadro's constant of that thing. For example, a mole of electrons will be 6.02 x 10^23 electrons. A mole of pencils will be 6.02 x 10^23 pencils. I hope that helps.
I love you omg
Hey Sir, how comes the number of atoms can be bigger than the number of molecules?
Are you given Avogadro's Constant (6.02 x 10 to the 23) in the exam, or do you have to memorize it?
memorize
@@gbaker0684 thanks
Thank you
This is really helpful Thankyou! But I don’t get why you times the 6.02 x 10 to the power of 23 by 2 when you’re working out the number atoms?
Molecules such as O2, H2, Cl2 etc have two atoms in each molecule (they're called diatomic). If you have one mole of molecules (ie 6.02 x 10^23 molecules) then you have two moles of atoms (ie 2 x 6.02 x 10^23 atoms).
Freesciencelessons Thankyou! That makes a lot more sense now
@@beckypotts8565 hmu, u cute
god bless you sir
I am confused as to why he times 1.806×10^23 by 3 again at 5:21, someone pls explain 😭
Because we are calculating the number of atoms in 3 moles of water molecules. Each water molecule contains 3 atoms (2 x hydrogen and 1 x oxygen). So we need to multiply the number of molecules of water by 3 to find the number of atoms.
@@Freesciencelessons Oh right TYYSSMM!! x
I don't understand what you did after you found the number of moles for the compounds?
In the exam, would it say ‘by using Avogadro’s constant calculate the number of atoms...’ or would it just say ‘calculate the number of atoms...’
No it would probably say "Calculate the number of atoms. Avogadro's constant is 6x10^23"
@@Freesciencelessons Thanks for the help!
Will I have to remember the moles' value (6.02 x10^23) in the test or is it provided?
I'm afraid that you'll have to learn it.
You will need to remember that!
In the last stage of the last question, when you are finding out the number of atoms, from the previous answer of molecules, why do you multiply by three?
Because each water molecule contains three atoms, so we multiply the number of molecules by three to find the number of atoms.
Thank you sir 😊
Wouldn't the answer to the last question be 5.418 x 10^*25* since you're multiplying it with 3 (with the invisible power of 1) ? Or is it the same as doing 6 x (avogadros constant) ??
oh ok That would only be the case if it was 10 and not 3.
would you be expected to get to the final answer in an exam or would 2 x (Avogadro's constant) be enough? thanks
I think that the actual number would be required. You'd be given Avogadro's constant in the exam.
@@Freesciencelessons I'm confused. In another comment in this video, you said that we will need to learn Avogadro's constant.
is avogadros constant number of molecules or atoms????
@daisy thank u my exam this morning 😭
How do I use Avogadro's constant to calculate the mass or Mr of one or two atoms?
Will the symbol be given in the exam?
do we need to know that 1 mole is equal to 6.02x10 23 ?
At 5:07 cant you just count the no of atoms then x it by avogadros constant to get the answer, would I still get all the marks?
Ye but that only works for only 1 mole of molecules
Hello sir please can u tell me whether to do past papers for new gcse. how is 9-1 different from old spec science
There are no past papers for the new GCSE. The spec is different in a number of ways, so I'm remaking all of the videos. However, there is still a lot of useful content in the old videos.
Freesciencelessons thank u so much Sir but should I do past papers anyway.
Well you could. It will help you develop a deeper understanding but you might end up learning things that are not on the 9-1 spec.
Freesciencelessons thank u so much I'll just revise and test myself and do few exam questions have u got any links to anyone who does maths new gcse
No problem. You could take a look at Corbettmaths and Hegartymaths. They might have what you need. I don't teach maths so I'm not really sure how good they are.
very cool
Why does 10 to the power of 23 always turn to 10 to the power of 24 at the end result?
Instant Play to make sure it is in standard form
How can I calculate this: 48g if Sulfur dioxide is provided. Calculate the number of moles of SO2. (I just saw your other video on this and calculated it to be 0.75? I don't know for sure if this is correct, because for some reason, avogadro's constant is given to me.) (Never mind sir. I think I figured out there is 4.515 x 10^23 molecules - but can you still check please?)
Where did I go wrong? SO2 = One sulfur (32 Ar) & Two Oxygens (16 + 16= 32) = 64 Mr. Number of moles is mass/Ar = 48/64 = 0.75. (0.75) x (6.02 x 10^23) gives us 4.515 x 10^23 molecules of Sulfur Dioxide. Or am I still wrong? If so, is it possible for you to show me a quick calculation for this?
Both your answers looks correct to me.
Thank you! I appreciate you checking my answer.
bossman, did you get this question from the chemistry sample paper 1 for edexcel. if so, set me the markscheme pls
bossman
What is the definition of avogadros constant ? One mole ?
1 mole or 6.02 x10^23
The number of atoms in one mole of a substance (6.02 x 10^23) xx
@@todd7744 then why he say number of molecules
2:15 why does the power of 10 go up from 23 to 24
In standard form, the first number must be between 1-10. So 6.02 x 10^23 is fine as the first number is between 1-10. However, if we multiply that by 3, we get 18.06 x 10^23. That's not allowed as the first number is greater than 10. So to correct for that, we increase the power by 10 instead, from 10^23 to 10^24. This gives us 1.806 x 10^24 as the correct answer.
big up wes
I didn’t understand the last one
easy clap
king
Where can I find the 2016 past papers?
My website. www.freesciencelessons.co.uk
Thanks but I can't find 2016 papers
Sorry, I didn't read your message carefully. I do apologise. I'm afraid that the 2016 papers are locked on the AQA website. Teachers can see them but we are not allowed to post links as they're used as mock exams. However, they are normally opened on AQA around a week before the exams, so as soon as they're available, I'll put the link up.
Okay thank you
can someone explain why times 2 at 3:49
so you can find the total number of ATOMS, not the molecules
I love you
hi dad
MY GGGGG
thanksssssssssssssssssssssssssssssssssssssssssssss
😭😢🖐🖐🖐🖐
What abt ions? Is ion same to atom?
Ion is an atom with a charge