Chemistry: Post your doubts here!

[helloolo]

I didnt know the nernst eqn part........that part just messed me up and the distialltion shit.......i didnt know wht to drw

sameeee i just drew some weird pipes

 

[Kanekii]

Good...How was yours?
But I think I messed up that table in Q2, still no worries it was of one mark only.

How did you do the last part of the last question?

 

[Hamnah Zahoor]

How did you do the last part of the last question?

the percentage purity one?
80.2%

 

[Hamnah Zahoor]

concentration of nitric acid*0.25 dm^3 = no.of moles
then i calculated the mass then the purity.

 

[A*****]

concentration of nitric acid*0.25 dm^3 = no.of moles
then i calculated the mass then the purity.

Concentration of acid wasn't given

 

[Hamnah Zahoor]

Concentration of acid wasn't given

it was to be taken from the graph

 

[Hamnah Zahoor]

Or again I am forgetting something....

 

[Hamnah Zahoor]

A***** Then how did you found the purity?

 

[Kanekii]

it was to be taken from the graph

Yes it had to be taken from the graph and it was conc of Cu2+ which was 0.19

 

[Hamnah Zahoor]

Yes it had to be taken from the graph and it was conc of Cu2+ which was 0.19

What was your answer?

 

[Kanekii]

What was your answer?

Mine was 60 something i think it was wrong.

 

[Hamnah Zahoor]

Mine was 60 something i think it was wrong.

What was your procedure?
And what was on the graph's other axis? I can't remember.

 

[blymphocytes]

Does anyone now have an idea about qp 31?

 

[blymphocytes]

sameeee i just drew some weird pipes

Me too.........what did you get as your percentage yield?

 

[Kanekii]

What was your procedure?
And what was on the graph's other axis? I can't remember.

Y-axis-Absorbance, X-axis-Conc of Cu2+
I used n=CV with volume of 250*10^-3
Found Mass using molar ratios since and then divided this by the increase in mass which was given *100
Though i think this was wrong or i made some error

 

[Hamnah Zahoor]

Y-axis-Absorbance, X-axis-Conc of Cu2+
I used n=CV with volume of 250*10^-3
Found Mass using molar ratios since and then divided this by the increase in mass which was given *100
Though i think this was wrong or i made some error

Now I remember,
we were suppose to calculate the percentage purity of copper
calculated conc. of copper = 0.19 mol dm^-3
volume 250 cm^-3
moles*Mr = 0.0475*63.5=3.0162g
purity = 3.0162/3.76 (if i remember the correct value)
80.2% was the answer

 

[Kanekii]

Now I remember,
we were suppose to calculate the percentage purity of copper
calculated conc. of copper = 0.19 mol dm^-3
volume 250 cm^-3
moles*Mr = 0.0475*63.5=3.0162g
purity = 3.0162/3.76 (if i remember the correct value)
80.2% was the answer

I just realised the stupid mistake that i made, i used the Mr of the whole compound instead of Cu.

 

[Hamnah Zahoor]

I just realised the stupid mistake that i made, i used the Mr of the whole compound instead of Cu.

You still might get 1 or 2 mark for procedure.

 

[A*****]

Yes it had to be taken from the graph and it was conc of Cu2+ which was 0.19

Yes Hamnah Zahoor we had to take it from the graph but that was Cu²+ concen

 

[Hamnah Zahoor]

Yes Hamnah Zahoor we had to take it from the graph but that was Cu²+ concen

Yes ...Sorry I just forgot.