pH of cation and anion salts

[105605391]

Hey, I was wondering if someone could lay out clearly how you find the pH of a conjugate salt or conjugate base from a weak acid or base, and if the pH of these has any effect on the total pH?

[Sunny Xiao 1A]

The conjugate base of a strong acid is weak, and the conjugate acid of a strong base is weak. Same is true for vice versa.
If you're finding the pH of a salt, you can use an ICE table and set the expression you get equal to Kb or Ka. After solving for x, you will get the concentration of H+ or OH- ions (depending on whether you used Kb or Ka). Then, you can calculate pH. Hope this helped!

[Kayla Arellano 1K]

Hey, I was wondering if someone could lay out clearly how you find the pH of a conjugate salt or conjugate base from a weak acid or base, and if the pH of these has any effect on the total pH?

When we find pH, we are finding the -log(H3O+) so it's not necessarily about the conjugate salt or conjugate base, its about the concentration of hydronium cation or hydroxide anion. However, we can find their pKa or pKb values if that's also what you were wondering.

To find the pH:
Step 1: Write out and balance the chemical equation
Step 2: Make an ICE chart
Step 3: Set up Ka (if given an acid) or Kb (if given a base)
Step 4: Solve for x which will be the concentration of H3O+ or OH-
Step 5: Plug concentrations into -log to find pH or pOH