Question

Give one example of each:
(a) Chemical reaction showing evolution of gas.
(b) Change in substance's colour during a chemical reaction.
(c) Chemical reaction showing change in temperature
(Short Answer)​

Answer 1

Answer:

(a) When Hydrochloric Acid is mixed with Zinc crystals (Evolution of Hydrogen gas)

(b) When Pottasium permanganate is mixed with Citric acid (Change in color from purple to transparent)

(c) When Sodium Hydroxide pellets are dissolved in Water (Increase in temperature of the solution: Exothermic reaction