November 26, 2024, 07:45:08 PM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: what is the new concentration of Cu++  (Read 3756 times)

0 Members and 2 Guests are viewing this topic.

Offline michenll

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-0
what is the new concentration of Cu++
« on: July 08, 2010, 01:18:23 AM »
10 ml of NH4OH 5M added to       80 ml of Cu2+ 0.1M

the reaction:

Cu2+ +4NH4OH(aq) <---> Cu(NH3)4 +4H2O


what is the new concentration of Cu++

equilibriumu K=21000
Logged

Offline AWK

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7976
  • Mole Snacks: +555/-93
  • Gender: Male
Re: what is the new concentration of Cu++
« Reply #1 on: July 08, 2010, 03:05:00 AM »
Show your attempt!
Logged
AWK

Offline Tahk

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-1
Re: what is the new concentration of Cu++
« Reply #2 on: July 08, 2010, 08:09:31 AM »
OK,

moles of cu2+ = c*v=0.1*0.08=0.008moles
moles of NH4OH  = c*v=5*0.01=0.05moles

Cu2+ +4NH4OH(aq)
1        :4
0.008   : 0.05
-0.008 : -0.0125

and I get that the4NH4OH(aq) is extra...

but in the second qoatuon I need to use again in the ions of Cu so I undedstand that I have a problem
Logged

Offline AWK

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7976
  • Mole Snacks: +555/-93
  • Gender: Male
Re: what is the new concentration of Cu++
« Reply #3 on: July 09, 2010, 04:23:09 AM »
Quote
Cu2+ +4NH4OH(aq) <---> Cu(NH3)4 +4H2O

0.008   : 0.05
-0.008 : -0.0125

Write down an expression for formation constant and put known data (concentrations) into it
Logged
AWK
Pages: [1]   Go Up
« previous next »
Sponsored Links