Chemistry Sim · pH Scale
Click any substance to see where it lands. Drag the slider to explore any pH value and watch the universal indicator color change.
0 = most acidic, 7 = neutral, 14 = most basic. Click a substance or drag the slider.
Explore pH values and see how universal indicator responds.
pH measures the concentration of hydrogen ions (H⁺) in a solution. Lower pH means more H⁺ ions — more acidic. Higher pH means fewer H⁺ ions and more OH⁻ ions — more basic. Each whole number change represents a 10× difference in concentration.
Universal indicator is a mixture of dyes that change color at different pH values. In strong acid it's red, in strong base it's purple, and at neutral pH it's green. It's like a chemical rainbow that tells you the exact acidity.
Check yourself