IAL Edexcel A2 Chemistry Unit 6 (Old syllabus)

Original post by Khazard

need some explanation to this,

I figured out we have to use KMnO4, and somehow get a positive Ecell value. Using the third equation makes sense, because vanadium v is being reduced to vanadium iv there, so we reverse the equation and use -1.00, then we add the two equations together? and their E values?
So in the end we get +1.51+-1.00, giving +0.51v?? (MS answer)
Or is it some other witchcraft because as far as i know Ecell = Ered - Eox, which gives (1.51--1.00) = 2.51v

What paper is this question from?

Reply 64

slightly_edited

10

Can someone please tell me if we get the Data booklet for unit 6 or not? Its mentioned in the unit 4 and 5 papers but not in the 6 papers

Reply 65

Original post by slightly_edited

Can someone please tell me if we get the Data booklet for unit 6 or not? Its mentioned in the unit 4 and 5 papers but not in the 6 papers

We do

Reply 66

Original post by slightly_edited

Can someone please tell me if we get the Data booklet for unit 6 or not? Its mentioned in the unit 4 and 5 papers but not in the 6 papers

No data booklet for paper 6. We will not need it. They won't ask for IR values and things like that. But they might ask what bonds might cause a peak in an IR spectrum.

Original post by saphira_jade

We do

Reply 67

Original post by CuriosityYay

Then for NMR?

Reply 68

we need the chemical shift values right? :frown:

Reply 69

Original post by saphira_jade

Then for NMR?

Original post by saphira_jade

we need the chemical shift values right? :frown:

I said we don't need it! Do a past paper and stop these questions. :bhangra:

Reply 70

Original post by CuriosityYay

I said we don't need it! Do a past paper and stop these questions. :bhangra:

Ok

Reply 71

Keka Ferdousi

6

Original post by amal29

Here's the physics thread: https://www.thestudentroom.co.uk/showthread.php?t=5938010

Thank you

Reply 72

lali000

do we have to know cobalt and manganese colours?

Reply 73

Original post by lali000

do we have to know cobalt and manganese colours?

Manganese is definitely. Cobalt is just to be sure.

You can remember Cobalt colors from the Cobalt(II) chloride paper used to test for water. Anhydrous is Blue, Hydrated is Pink.

Manganese(II) ions are very pale pink and can be described as colorless. (Don't use the word purple, it is reserved for manganate 7)
Manganate(VII) ions are purple.

If you add alkali like NaOH or NH3 to Mn²⁺ it will turn to white/off-white/beige/light brown/pale brown (use off-white) precipitate, which will darken (turn darker brown when left standing as it gets oxidised to (manganese(III) oxide Mn₂O₃ and then) manganese(IV) oxide MnO₂

Reply 74

Sandar456

Original post by slightly_edited

Can someone please tell me if we get the Data booklet for unit 6 or not? Its mentioned in the unit 4 and 5 papers but not in the 6 papers

They will give if necessary

Reply 75

Khazard

7

November 2018

Original post by saphira_jade

What paper is this question from?

Reply 76

Khazard

7

Original post by sickomode

Ecell= Ered-Eoxd
=1.51-+1.00
u NEver change the sign of Evalues
u reverse the equation but values sign remains same

in the third equation, vanadium is getting reduced not oxidized, so how can one plug that value in Eoxd?
and im sure if the equation is reversed, e value reverses

I figured it out, you have to add the two equations to form a redox equation with the manganate ions and REVERSED vanadium equation(3rd), so even E values are added, so E ovr will be 1.51+(-1.00) = 0.51v

(edited 4 years ago)

Reply 77

Sandar456

Do you think May 2019 chemistry unit6 will be easy or hard?

Reply 78

Original post by Sandar456

They will give if necessary

They won't give. NO DATA BOOKLET for paper 6

Reply 79