copper concentration (1 Viewer)

[lukebennett]

ok i have the answer.
CuSO4 conc=0.050 mol L-1
250mL thus to find the number of moles, 0.050x0.25L=0.0125 moles CuSO4
thus 0.0125 moles Cu2+ initially
then 0.325g are removed from solution =0.0051 moles Cu
thus number of moles finally= 0.0125-0.0051=0.0074 moles
c=n/v=0.0074/0.25=0.0296mol L-1
this is the answer i actually got in the exam. i originally only recalled the no moles i had found.so i think 0.03 would be ok

 

[dafidav]

ok i have the answer.
CuSO4 conc=0.050 mol L-1
250mL thus to find the number of moles, 0.050x0.25L=0.0125 moles CuSO4
thus 0.0125 moles Cu2+ initially
then 0.325g are removed from solution =0.0051 moles Cu
thus number of moles finally= 0.0125-0.0051=0.0074 moles
c=n/v=0.0074/0.25=0.0296mol L-1
this is the answer i actually got in the exam. i originally only recalled the no moles i had found.so i think 0.03 would be ok

we have a winner!

 

[xeriphic]

hmm I did the same as Zepplin and lukebennet, calculate the original mass of copper within that solution, then subtract with the mass of the deposit, then work out new mole hence the concentration

 

[sig]

yeah I did what u guys above did but I was thinking

how can u deduct moles of Copper from Moles of Copper SULFATE?

Your not considering the sulfate at all when you calculate the concentration of Copper Sulfate?

 

[DavidB]

No no no ... im sure it was 0.004 or sumthn with 0's and a 4.

U guys forgot that for every mole of Cu2SO4, there are TWO moles of CU+2, and you gotsta take that into account wen calculating.. I did it the same way u all did, and realised nope..thas rong.

 

[nit]

there is only one mole of Cu2+ ions for every mole of copper sulfate. 0.03/0.0295M (i don't think they'll be too picky with sig figs tho I hope they r ) is right.

 

[wesleyyuk]

i got 0.03 or sth..but like i remember i have to compare the proportion of Cu2+ with CuSo4, then times according to the equation n=cV to find the concentration!

 

[yulia]

Maybe I'm thinking of another question...

But I did get 0.03 or 0.003 whatever...

But wasn't there something you had to do to THAT answer once you got it?

Or am I thinking of something else I don't know how you all remember the questions.

 

[martian_man86]

i got 0. (insert number of zeroes necessary - i dont remember) 295...
in other words, 0.03 (or however many 0s), same as most people, what a guess