Chemistry: Post your doubts here!

[holoholo]

Can you please explain this ?

 

[holoholo]

Chemistry: Post your doubts here!
I answered this previously on that link. See if it helps

Thank you


View attachment 59642

Can you please explain this ?

 

[Sirius48]

Are we required to know this? I've never heard of EDTA :/

No, don't worry, I do not think you need to know it for A-levels. I just answered since I studied about it in biochemistry.
Just for general knowledge, EDTA stands for Ethylene-Diamine-tetra-Aceticacid and is either used as an anticoagulent (prevents blood clots) for preserving blood specimens or as a chelating agent that binds calcium with other metals.

 

[qwertypoiu]

No, don't worry, I do not think you need to know it for A-levels. I just answered since I studied about it in biochemistry.
Just for general knowledge, EDTA stands for Ethylene-Diamine-tetra-Aceticacid and is either used as an anticoagulent (prevents blood clots) for preserving blood specimens or as a chelating agent that binds calcium with other metals.

Ah I see! Thank you

 

[qwertypoiu]

View attachment 59642

Can you please explain this ?

Whatever is not absorbed is the color of the substance.

For C, 650nm is least absorbed so color is red.
For D, 450nm is least absorbed so it's blue.

 

[holoholo]

Whatever is not absorbed is the color of the substance.

For C, 650nm is least absorbed so color is red.
For D, 450nm is least absorbed so it's blue.

Isn't it 400 for D ?

 

[qwertypoiu]

Isn't it 400 for D ?

But violet isn't in the option

 

[The Sarcastic Retard]

Here you go. It would be a really crowded structure in a space fill model.

Thanks.

 

[holoholo]

But violet isn't in the option

how about this question ?

Value in c(i) is 7 x 10^-7 . in the mark scheme it's written concentration of product if 0.1 but shouldn't it be 0.1 - (7 x 10^-7 )?

 

[The Sarcastic Retard]

how about this question ?

Value in c(i) is 7 x 10^-7 . in the mark scheme it's written concentration of product if 0.1 but shouldn't it be 0.1 - (7 x 10^-7 )?

Why will u do that?

 

[holoholo]

Because at first the concentration is of Ag+ is 0.1 then it is reduced to 7 x 10^-7 . As it is 1:1 mole ratio shouldn't the concentration of the product increase by 0.1 - 7 x 10^-7 ?

 

[The Sarcastic Retard]

how about this question ?

Value in c(i) is 7 x 10^-7 . in the mark scheme it's written concentration of product if 0.1 but shouldn't it be 0.1 - (7 x 10^-7 )?

You made ur equation of Kc.
Just substitute the values and find [NH3(aq)]
o.1 is conc of silver nitrate soln and (7 x 10^-7 ) is conc of Ag.

 

[holoholo]

You made ur equation of Kc.
Just substitute the values and find [NH3(aq)]
o.1 is conc of silver nitrate soln and (7 x 10^-7 ) is conc of Ag.

Yes but we need to use the concentration of Ag(NH3)2 not of silver nitrate

 

[Abdullahassan_99]

Can anyone plz explain me why the answer for chemistry may june 2007 v1 p1 first answer is C?

 

[Awesome12]

View attachment 59644 Can anyone plz explain me why the answer for chemistry may june 2007 v1 p1 first answer is C?

= (Mass no x Relative Abundance) / (Relative Abundance)

= {(10 * 1) + (11 * 4)} / 1 + 4

= 10.8

There is no peak for the mass no. 12, so we don't need to consider it. Note: Even if you consider it, it will be 12 * 0 = 0

 

[holoholo]

Explanation for question (c) please ?

 

[holoholo]

Can someone please sketch this graph ?

 

[The Sarcastic Retard]

View attachment 59647

Explanation for question (c) please ?

From part (a) you can see that there is no effect of Cl- ion on production of O2 where as if u see the reaction of chlorine the equilibrium shifts to form more chlorine and moves in direction of electrons thus the E value will be less positive that is it will decrease.

 

[Muhammad Amer]

I don't know if it has been uploaded here before, but I've been looking for a PDF version of this book for ages, and I found it.

It can be downloaded from here.

You need a torrent down-loader to download it, μtorrent should be fine.

 

[Muhammad Amer]

I don't know if it has been uploaded here before, but I've been looking for a PDF version of this book for ages, and I found it.

It can be downloaded from here.

You need a torrent down-loader to download it, μtorrent should be fine.

I believe the CD has been uploaded here before, so you could find it by using the search bar in xtremepapers. If not, here is a torrent link for the CD.