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Substituting the equilibrium concentrations into the equilibrium (Kb) expression

ID: 501734 • Letter: S

Question

Substituting the equilibrium concentrations into the equilibrium (Kb) expression and solving for x gives the concentration of OH-: ____M

What is the pOH of this solution?

What is the pH of at the equivalence point (find pH from pOH in previous step):

CH3COO- acts as a weak base (ag) OHaq) The equilibrium-constant (Ka) expression for this reaction is: CH3COOH) DOH Kb CH COO The Kb for CH3COO- can be calculated from the Ka of acetic acid. The concentration of CH3COO- can be plugged into an ICE table to solve for the concentration of OH OH CH3COO H2O CH3COOH (ag) (aq) Initial Concentration (M) Change in Concentration (M) Equilibrium Concentration (M)

Explanation / Answer

pOH is define as negative logarithm to the base 10 of concentration of hydroxyl ion.

i.e., pOH = - log([OH-])

Therefore, by substituting the value of concentration of OH calculated into above equation gives you pOH of the solution.

For pH, subtract pOH from 14. i.e., pH = 14 - pOH