pHs by

pHs by https://padlet.com/n8dsouza/4o8qipwr8rs49fsg en-us 2022-10-05 08:20:03 UTC 2023-03-02 20:21:09 UTC hello@padlet.com Calculating pHs n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327178493 2022-10-05 08:20:37 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327178493 Calculating pH in Strong Acids n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327185290 HA → H⁺ + A⁻
Relationship between HA and H⁺ is 1:1 therefore:
[H⁺] = [HA]
pH = -log[HA]]]> 2022-10-05 08:25:56 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327185290 Definition of pH n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327186451 pH = -log[H⁺]]]> 2022-10-05 08:26:48 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327186451 Calculating pH in Weak Acids n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327187330 HA ⇄ H⁺ + A⁻
Therefore:
K_a = [H⁺] [A⁻] / [HA]_eqm
Since [H⁺] = [A⁻],
K_a = [H⁺]² / [HA]_eqm
and since [HA]_start = [HA]_eqm
K_a = [H⁺]² / [HA]_start
By rearranging we can get:
[H⁺] = √(K_a [[HA]_start)
pH = -log√(K_a [HA]_start)]]> 2022-10-05 08:27:31 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327187330 Assumptions for calculating pH in Weak Acids n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327215733 1) The concentration of H⁺, [H⁺] is equal to the concentration of A⁻, [A⁻] during equilibrium.
2) The change is concentration of HA at the start, [HA]_start to HA in equilibrium, [HA]_eqm is negligible enough that [HA]_start= [HA]_eqm
3) We can ignore any H⁺ from the dissociation of water as it is negligible in comparison to the concentration of H⁺ from the acid.]]> 2022-10-05 08:49:43 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327215733 Assumptions of calculating pH in Strong Acids n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327227831 1) We can ignore any H⁺ from the dissociation of water as it is negligible in comparison to the concentration of H⁺ from the acid.
2) The acid fully dissociates into its ions.]]> 2022-10-05 08:58:28 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327227831 Equilibrium constant of acid dissociation, Kₐ n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327246148 K_a = [H⁺] [A⁻] / [HA]_eqm
Equilibrium Constant changes with temperature.]]> 2022-10-05 09:13:34 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327246148 Equilibrium constant of water dissociation, Kw n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327254050 K_w = [H⁺] [OH⁻]
Equilibrium Constant changes with temperature.]]> 2022-10-05 09:19:48 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2327254050 Calculating pH in Strong Bases n8dsouza https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2328870124 AkOH → Ak⁺ + OH⁻
Relationship between AkOH and OH⁻ is 1:1 therefore:
K_w = [H⁺] [OH⁻]
K_w = [H⁺] [AkOH]
By rearranging we can get:
[H⁺] = K_w / [AkOH]
pH = -log(K_w / [AkOH])]]> 2022-10-06 06:56:28 UTC https://padlet.com/n8dsouza/4o8qipwr8rs49fsg/wish/2328870124