Question

Which of the four test tubes containing the following chemicals shows the brisk

effervesence while dilute acetic acid was added to them ?

(i) KOH (ii) NaHCO3 (iii) K2CO3 (iv) NaCl​

Answer 1

Metal carbonates and metal hydrogen carbonate react with acids to form metal salt of acid, water and carbon dioxide and carbon dioxide is evolved as a gas and hence shows effervescence.

So

NaHCO3+CH3COOH------>CH3COONa + CO2+H2O

K2CO3+CH3COOH------>CH3COOK + CO2+ H2 O

Option ii and iii is correct