Chemistry: Post your doubts here!

[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.

 

[A*****]

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

Yes this is correct and I got the same answer

 

[A*****]

Yes ...Sorry I just forgot.

No probs

 

[Hamnah Zahoor]

No probs

 

[FaDGus]

I used 70 grams per mole for the chlorine molecule. Is that acceptable?

P.S. The number of significant figures wasn't specified anywhere.

It was supposed to be 71 since 35.5 multiplied by 2 = 71

 

[Maiday Holsey]

It was supposed to be 71 since 35.5 multiplied by 2 = 71

Will they accept 70?

 

[studyingrobot457]

Will they accept 70?

most probably not

btw, the answer for the number of atoms is 3.93*10^21 because Chlorine is diatomic, so u had to double the number of atoms

 

[Maiday Holsey]

most probably not

btw, the answer for the number of atoms is 3.93*10^21 because Chlorine is diatomic, so u had to double the number of atoms

Yes, but all the data given was for the chlorine molecule, not chlorine atom.

 

[studyingrobot457]

Yes, but all the data given was for the chlorine molecule, not chlorine atom.

no
The part two was for number of chlorine atoms if u read the question properly

 

[Maiday Holsey]

Which type of isomerism was in the last q? Pls tell me it was optical ((((

 

[studyingrobot457]

Which type of isomerism was in the last q? Pls tell me it was optical ((((

yeah optical

 

[helloolo]

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

73 you

 

[blymphocytes]

73 you

Samee

 

[blymphocytes]

Who did paper 31?

 

[helloolo]

Samee

That good atleast we got 3 marks lol. What about your MnZ+