Question

Which of the following activity you should never do in a chemistry lab?

• A. Add water to concentrated HCl
• B. Add water to sulphur powder
• C. Add water to potassium permanganate crystals
• D. Add water to zinc granules

Answer 1

The correct option is A

Add water to concentrated HCl

Adding water to concentrated HCl should be avoided in a chemistry lab because:
a) A large amount of heat is released.
b) A layer of hot weak acid solution is formed, which boils and sprays around.
c) It forms extremely concentrated solution of acid initially. So much heat is released that the solution may boil very violently, splashing concentrated acid out of the container and all this because acid-water reaction is exothermic and corrosive.