Calculating pH of a Weak Acid
Chemistry discussion, revision, exam and homework help.
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Calculating pH of a Weak AcidCould somebody please answer this question for me and show me your working so I can hopefully see how it's done? I'm fine with strong acids that completely ionise but I'm struggling with weak acids.
Calculate the pH of 0.01 mol.dm-3 propanoic acid (a weak acid, which partially ionises and has a dissociation constant of 1.34 x 10-5 mol.dm-3) at 298K. -
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Re: Calculating pH of a Weak AcidDo you know the formula for the dissociation of a weak acid?(Original post by TFish89)
Could somebody please answer this question for me and show me your working so I can hopefully see how it's done? I'm fine with strong acids that completely ionise but I'm struggling with weak acids.
Calculate the pH of 0.01 mol.dm-3 propanoic acid (a weak acid, which partially ionises and has a dissociation constant of 1.34 x 10-5 mol.dm-3) at 298K.
ka = [H+][A-]/[HA]
assume [HA] is constant -
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Re: Calculating pH of a Weak AcidThis plus the fact that [H+]=[A-](Original post by charco)
Do you know the formula for the dissociation of a weak acid?
ka = [H+][A-]/[HA]
assume [HA] is constant
