Question
Calculate the pH at the equivalence point of 25.0 mL of a 0.100 M acetic acid, CH3COOH, titrated with a 0.100 M sodium hydroxide, NaOH. Ka of acetic acid is 1x10^-5
Answers
You must recognize what you have at the equivalence point.
CH3COOH + NaOH ==> CH3COONa + H2O.
At the equivalence point, we have converted all of the CH3COOH to CH3COONa (sodium acetate) so we have M x L = 0.1 x 0.025 = 0.0025 moles sodium acetate. That is in a volume of 50 mL (the other 25 came from 25 mL of 0.1 M NaOH). The pH will be determined by the hydrolysis of water. If we call acetate, Ac^-, and acetic acid HAc, then
Ac^- + HOH ==> HAc + OH^-
Kb for acetate = (Kw/Ka) = (HAc)(OH^-)/(Ac^-).
Set up an ICE chart and solve.
Post your work if you get stuck.
CH3COOH + NaOH ==> CH3COONa + H2O.
At the equivalence point, we have converted all of the CH3COOH to CH3COONa (sodium acetate) so we have M x L = 0.1 x 0.025 = 0.0025 moles sodium acetate. That is in a volume of 50 mL (the other 25 came from 25 mL of 0.1 M NaOH). The pH will be determined by the hydrolysis of water. If we call acetate, Ac^-, and acetic acid HAc, then
Ac^- + HOH ==> HAc + OH^-
Kb for acetate = (Kw/Ka) = (HAc)(OH^-)/(Ac^-).
Set up an ICE chart and solve.
Post your work if you get stuck.
help me solve "use the results of your experiment to determine the various endpoints and then plot a titration curves expected of the two indicators, volume of NaOH (x-axis) pH range of indicators (y-axis)
results are :for bromothymol blue indicator average title volume is27.3 and for phenolphthalein indicator average average titre volume is 27.77
results are :for bromothymol blue indicator average title volume is27.3 and for phenolphthalein indicator average average titre volume is 27.77
Related Questions
25.0 CM3 OF 0.100M acetic acid is titrated with 0.900M of NaOH. Ka for acetic acid =1.85*10^-5. calc...
Assuming that Ka is 1.85 *10-5 for acetic acid, calculate the pH at one-half the equivalence point a...
the acid dissociation constant for acetic acid is 1.85x10^-5. Calculate the pH at the equivalent poi...
the acid dissociation constant for acetic acid is 1.85x10^-5. Calculate the pH at the equivalent poi...