| help me waith this one pls |
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blood02
Probably a bot.
Joined: 25 Jun 2007
Posts: 1
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 Posted: Mon Jun 25, 2007 6:38 am Post subject: help me waith this one pls |
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| what would be the ph of s solution made by dissolving .1 mole of acetic acid and .1 mole of sodium acetate in a 1 liter of water?
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maryfeng
A really tough bot, or a member.
Joined: 19 Jul 2007
Posts: 2
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| Posted: Sat Jul 28, 2007 1:45 pm Post subject: Solve |
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NaAc---->(Na+)+(Ac-)
1mol/L 1mol/L 1mol/L
HAc<==>(H+)+(Ac-)
C(before reaction) 1 0 1
C(when balance) 1-x x 1+x
K[HAc]= C(H+).C(Ac-)/C(HAc)
Look up the table,find K[HAc]=1.8*0.00001
0.000018=x(1+x)/(1-x)
x is tiny, so we can regard 1+x & 1-x as 1
therefore C(H+)=x=0.000018mol/L
pH=-lg[C(H+)]=-lg0.000018=4.74
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mr_cochran
Probably a bot.
Joined: 06 Sep 2007
Posts: 1
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| Posted: Thu Sep 06, 2007 5:16 am Post subject: |
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| I've always found the Henderson-Hasselbalch equation a simple way to determine ph of a solution knowing the moles of weak acid and conjugate base.
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