AS Chemistry Edexcel Unit 1 June 2020 Paper - Dr Hanaa Assil

[@wazowski97]

Thank you for this! You're a lifesaver

[@marwababiker7457]

in question 19 how did you know chromium was a +3

[@IHunter-me9tz]

The valency

[@repeatandtakeaverage7081]

Hello Ms Thank you for your effort, I have a small question at 25:25 why did we use the moles of ammonium dichromate instead of deducing Nitrogen moles and using it

[@rozarahman1671]

Because the ratio is same as nitrogen

[@emanilyas4749]

amazing channel best teacher

[@drhanaaassil-chemistryteac9433]

Thank you! 😃

[@lakshikawijesinghe4347]

thank you miss, sry Dr. You are a lifesaver!!

[@carlahadad814]

In question 6 why did we take the last two isotopes only

[@thetaismeta]

why does 22b) ii) have to be in displayed formula? cant we do it in structural formula? (44:23)

[@aliyak9015]

for the multiple choice question 6a, why are the smaller peaks not included in the calculation?

[@marwababiker7457]

did u figure this out

[@Thefluffypets1]

@@marwababiker7457it’s because those are not isotopes! Isotopes are always whole number as they are the sum of proton and neutron and to find Ar you only use isotopes. So, that’s why the smaller peaks are not included. These smaller peaks are due to either 63 Cu 2+ and 65 Cu 2+… Mass to charge ratio gives us 63/2= 31.5 +1 And 65/2 =32.5 +1

[@justsomeone5660]

Thank you​@@Thefluffypets1 Could u also pls explain why we divide by 66 instead of 100?

[@vibhakumar7743]

@@Thefluffypets1 Hey! I didnt really get the explanation; like the m/z ratio may be decimal but that because it was just divided by 2? thank you in advance :)

[@Notpicdoinyomom]

The relative abundance given on the graph is actually upto 50 instead of 100 and we divide the m/z values by the summation of the 2 relative abundance taken​@@justsomeone5660

[@zunaina1957]

um i didnt understand how gallium has 18 electrons

[@Arya_Takeda]

Same I thought it was 28 after removing 3

[@israthoque1612]

Assalamu alaikum ma'am can you please explain why did you divide in number 6 part a with 66 instead of 100?

[@drhanaaassil-chemistryteac9433]

We should divide by the total of the two abundances, in this case it is 66 instead of 100

[@primeroxx]

2:15 how do we know zinc is 2+ if its a transition metal

[@gustybot]

its something that theyre assuming u already know from gcse

[@zihanhossain4394]

Really appreciate these

[@LolwaA-q5q]

Can you please do for Jan 2020 unit 1?

[@allaboutkpop1621]

Assalamualaikum mam the video was very helpful , mam can u please do january 2020 paper 1

[@primeroxx]

24:30 how do uk chromium valency is 3

[@marwababiker7457]

i have the same question did u figure it out?

[@gustybot]

yeah idk

[@waleedomari8042]

Hello at 24:24 how do you know that the charge of chromium is 3+?

[@danaalyafei9749]

I don’t know if this is useful now , but basically there is 7 oxygen in the compound at the start and water has 4 oxygen atoms ( in the product) So just do 7-4=3 . Hope this help

[@waleedomari8042]

@@danaalyafei9749 thank you! Yes it’s very useful 😊

[@aki-hb5vh]

hi miss number 20 part b) ii) i dont understand how where did u draw line of symmetry in that molecule and how you classified it as trans

[@shireenrashida1356]

Loved it thanks Do you have topic explanation videos

[@drhanaaassil-chemistryteac9433]

kzbin.info/www/bejne/q4qrl4inlsmqkLs

[@Black-iu5bd]

Can u upload the Jan2020 unit 1 solution IAL

[@drhanaaassil-chemistryteac9433]

will try to

[@birdie7344]

did u upload it?@@drhanaaassil-chemistryteac9433

[@deenamirza322]

Assalamualaikum. Can anyone explain me no.11? Doesn't ionic radius decreases as the no. of protons increases? So here, Ga3+ has the most no. protons. But we did choose Al3+. Why?

[@drhanaaassil-chemistryteac9433]

Ga3+ has 18 electrons 3 energy levels, the other options have 10 electrons 2 energy levels

[@tawsiftahrim6032]

@@drhanaaassil-chemistryteac9433 ain't it supposed to have 28 electrons?

[@gustybot]

shielding matters more than the number of protons usually and gallium has more shielding

[@primeroxx]

7:40 how do uk its out of 66

[@creativityandfun602]

The relative abundance is not 100. It's 46 + 20, as we can see from the graph. The total relative abundance of the isotopes shown on the graph is (46+20 = 66). Hope this helps 😊

[@SamiraAbdullahi-qf1nd]

U helped me thanks 😊​@@creativityandfun602

[@zihanhossain4394]

Sharing with my classmates

[@BLACKWHITE-og3rg]

thanks misss

[@amanee6607]

hi, you forgot the type of reaction in the last sub part of the last question. thank you. this was very helpful otherwise.

[@drhanaaassil-chemistryteac9433]

You are right, I mentioned it but did not write it. Thank you for pointing that out. I will have it fixed.

[@muckingoff]

@@drhanaaassil-chemistryteac9433 Is it electrophilic addition?