✦ Class 10 · Science

Acids, Bases and Salts

Why does lemon juice turn red litmus blue, but soap turns it red—when they're both slippery liquids you'd think they're the same thing?

How it looks

A real board, not a video.

This board is from a different Science lesson — yours will look like this. She writes and draws while she explains, and stops to check you followed.

What exactly are H⁺ and OH⁻ ions? Are they real things I can see?
How much more acidic is pH 2 than pH 4? Do I multiply or add?
Why is adding water to acid so dangerous but adding acid to water is safe?
If acetic acid is weak, does that mean it's less acidic or just has fewer H⁺ ions?
When an acid and base react and make a salt, is the salt always neutral on the pH scale?
If water is inside the crystals, does that water count toward what I drink if I accidentally eat copper sulphate?

Class 10 Science

Interactive. NCERT-aligned. Any time, anywhere.