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edexcel as chemistry and biology 23 nd 24th 2019

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how to calculate this?
image-3fc5c997-015d-4284-9dae-49f463fd12205486844515250960766-compressed.jpg.jpeg
ans is c but why?

image-d89692e3-9241-49bd-bcf8-8267704b29a51692171043226187544-compressed.jpg.jpeg
Reply 22
Avatar for CocoLal
CocoLal
3
Original post by dsn_o_u_r_e_e_n
how to calculate this?
image-3fc5c997-015d-4284-9dae-49f463fd12205486844515250960766-compressed.jpg.jpeg


its the most basic thing ever

mr = m / n

once you get mr use periodic table
Original post by CocoLal
its the most basic thing ever

mr = m / n

once you get mr use periodic table


ugh i didn't use the periodic table..can u help me the other one too?
Reply 24
Avatar for CocoLal
CocoLal
3
Original post by dsn_o_u_r_e_e_n
ans is c but why?

image-d89692e3-9241-49bd-bcf8-8267704b29a51692171043226187544-compressed.jpg.jpeg


20% decomposes so 80% is left.

80% x 500 = 400cm^3

so its B
but hey i got 71 and how can i relate further?
Original post by CocoLal
20% decomposes so 80% is left.

80% x 500 = 400cm^3

so its B

but Answer is C!
Reply 27
Avatar for CocoLal
CocoLal
3
Original post by dsn_o_u_r_e_e_n
but Answer is C!


Ohhh it says total volume of gas. So you have to add on the hydrogen too
Original post by CocoLal
Ohhh it says total volume of gas. So you have to add on the hydrogen too


can u show the working?
image-51c10be8-5514-4518-a605-98763f365a0b147064673263232944-compressed.jpg.jpeg calculation is 30×(30/1000)0.025 i understood the equation but from where is the other 30 coming from?
Original post by dsn_o_u_r_e_e_n
why do we divide by moles and do we always take the mass of solution in delta h calculation apart from neutralization questions?


yes we always take the mass of solution
Original post by Bloomy_blue
yes we always take the mass of solution


ok and why do we divide by moles?
how's everyone's preparation? this thread is so unactive..I'm literally crying.😖
image-7cbebc14-5450-41d4-a87c-e8737e7194989209235791302396197-compressed.jpg.jpeg

why not A be the ans? why C?
are you guys sitting the edexcel a (snab) biology paper 1 on the 21st of may? please let me know!?
Original post by dsn_o_u_r_e_e_n
image-7cbebc14-5450-41d4-a87c-e8737e7194989209235791302396197-compressed.jpg.jpeg

why not A be the ans? why C?
Original post by myth0000
are you guys sitting the edexcel a (snab) biology paper 1 on the 21st of may? please let me know!?

YES
Original post by dsn_o_u_r_e_e_n
image-7cbebc14-5450-41d4-a87c-e8737e7194989209235791302396197-compressed.jpg.jpeg

why not A be the ans? why C?


fluorine is the most electronegative element in periodic table so fluorine is not polarised
guyss how was the xm? i did a mistake i didnt multiply the atom economy by 100.will that deduct marks?😱
Reply 38
Avatar for AsithU
AsithU
14
I thought it was pretty easy
Original post by dsn_o_u_r_e_e_n
guyss how was the xm? i did a mistake i didnt multiply the atom economy by 100.will that deduct marks?😱


probably not coz multiplying by 100 gives %. mark won't probably be cut if u did not give the %sign

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