Activity 2.3 NCERT Class 10 Science, Chapter 2 Acids, Bases, and Salts.
Brief procedure: Activity 2.3 asks us to react zinc granules with various acids and observe the flammability of gas formed.
We see bubbles coming out vigorously with strong acids. This gas burn when we bring the candle to it.
Zinc also react with weak acids like acetic acid, but here gas formation is slow.
Zinc reacts with acids and forms its salt and hydrogen gas. Hydrogen gas liberates as the bubble. When we bring the flame to this gas, it burns as hydrogen is highly flammable.
Zn + H2SO4 ———> ZnSO4 + H2
Weak acid does not dissociate quickly in water. So its reaction with zinc is slower as compared to strong acids like Hydrochloric acid and sulphuric acid.
Reference: NCERT textbook for class 10 Science.