Activity 2.10 NCERT Class 10 Science, Chapter 2 Acids, Bases, and Salts
Procedure:
Activity 2.10 asks us to add a few drops of concentrated sulphuric acid slowly into a beaker containing water and see if heat produces.
Observation:
When we touch the bottom of the beaker, it feels hot
Explanation:
Diluting an acid or base into water is an exothermic reaction. Here hydrogen ion interacts with a water molecule and forms hydronium ion. In this process, heat evolves which make the beaker hot.
H2SO4 ——> H+ + HSO4–
H+ + H2O ——> H3O+
Warning:
- We add acid to water. If we add water to acid, the high concentration of acid may produce a violent exothermic reaction.
- Concentrated acids and bases are corrosive; no person should touch it with bare hand or skin. In case a few drops spill on the body, a person should wash it with plenty of water.
Next: PH of common substances, Activity2.11.
See also: Concentrated acids do not turn litmus paper into red, activity 2.9.
Ref: Hydronium ion.
