Easy Mnemonics to Master Solubility Product and pH Concepts

1. Ionic Product of Water (Kw = [H⁺][OH⁻] = 1 × 10⁻¹⁴ at 25°C)

Mnemonic:

“Hot Water Has Opposites Multiplied.”

Hot → H⁺

Water → OH⁻

Has Opposites Multiplied → H⁺ × OH⁻ = Kw

✅ Helps remember:

Kw = [H⁺][OH⁻] = 1 × 10⁻¹⁴ (at 25°C)

 2. pH = –log[H⁺]

Mnemonic:

“pH is the Power of Hydrogen.”

p → power (–log)

H → [H⁺]

✅ Helps remember:

pH = –log[H⁺]

Lower [H⁺] → Higher pH (basic)

Higher [H⁺] → Lower pH (acidic)

3. pOH = –log[OH⁻]

Mnemonic:

“pOH = Power Of Hydroxide.”

p → power (–log)

OH → hydroxide ion

✅ Helps remember:

pOH = –log[OH⁻]

More OH⁻ → Lower pOH (more basic)

4. pH + pOH = 14 (at 25°C)

Mnemonic:

“pH and pOH always say 14 Okay!”

✅ Helps remember:

At 25°C,

pH + pOH = 14

So if pH = 3, pOH = 11, etc.