Pure water has pH:

**The reasoning** The pH scale measures how acidic or alkaline (basic) a solution is, ranging from 0 to 14. It's based on the concentration of hydrogen ions (H⁺) in the solution. Pure water naturally splits into equal amounts of H⁺ and OH⁻ ions through a process called self-ionization: H₂O ⇌ H⁺ + OH⁻ Because the H⁺ and OH⁻ concentrations are **exactly equal** in pure water, it's perfectly **neutral** — neither acidic nor basic. The neutral point on the pH scale is defined as **pH 7**. Think of it like a balance scale: equal weights on both sides = neutral = 7. **Why the wrong options tempt you** Students sometimes guess **6 or 8** thinking "close enough" or confusing pure water with slightly contaminated water (rainwater absorbs CO₂ and becomes weakly acidic, around pH 5-6). Option **5** might tempt those confusing pure water with common drinks like Coke or orange juice. **Quick takeaway** Pure water = neutral = pH 7 — remember it as the **perfect middle** of the pH scale, like the equator on a map!