Acetic acid has K_a = 1.8 10^-5. Show the reasoning and steps needed to calculat
ID: 524211 • Letter: A
Question
Acetic acid has K_a = 1.8 10^-5. Show the reasoning and steps needed to calculate the pH which results when 101 mL of 0.600 M acetic acid is mixed with 101 mL of 0.200 M potassium hydroxide. Start this and all chemistry problems by writing appropriate balanced chemical reactions. Show formulas with symbolic representations (means show the symbols) for any calculations you perform. Just don't simply perform the calculations. Calculate the number of grams of copper that can be plated from CuSo_4 (aq) in an electrolysis (electroplating) setup by a current of 150 amperes flowing through the electroplating device for one hour. Start this and all chemistry problems by writing appropriate balanced chemical reactions. Show formulas with symbolic representations (means show the symbols) for any calculations you perform. Just don't simply perform the calculations. Important data is found on the cover page.Explanation / Answer
Q1.
the acid:
Ka = [H+][A-]/[HA]
mmol of acid = MV = 101*0.6 = 60.6
mmol of base = MV = 101*0.2 = 20.2
after reaction
acid left = 60.6-20.2 = 40.4
conjugate formed = 20.2
then, the pH is given by buffer equation
pH = pKa + log(A-/HA)
pH = 4.75 + log(20.2/40.4) = 4.44897
The formulas:
CH3COOH <--< CH3COO- + H+
KOH + CH3COOH <--> KCH3COO + H2O