Lemon juice versus soap
Lemon juice stings and tastes sour (acidic), while soap feels slippery and bitter (basic). The pH scale ranks them from sour acids to slippery bases, with pure water sitting neutral in the middle at 7.
From 0 to 14
The pH scale runs from 0 to 14. Below 7 is acidic (more H⁺ ions), exactly 7 is neutral (pure water), and above 7 is basic (more OH⁻ ions). Lemon juice is acidic; soap is basic.
Simulation · The pH scale
pH 7
pH 7 — neutral
Slide across the pH scale and watch a substance switch from acidic to neutral to basic.
Lab · Acid, base, or neutral?
- Set the slider to pH 2 (like lemon juice).
- Move to pH 7 (pure water).
- Move to pH 12 (like bleach).
What you should see: pH 2 is strongly acidic, pH 7 is neutral, and pH 12 is strongly basic.