Question

from an experiment to study the properties of acetic acid. Answer the following questions: 2
a) Name the substances which on addition to acetic acid produce carbon dioxide gas. Give relevant chemical
equation for the above?
b) How is CO2 gas tested in the laboratory?

Answer 1

(a) Sodium Carbonate and Potassium Hydrogen Carbonate can be added to obtain carbondioxide gas.

As acetic acid is an acid when it reacts with metal carbonates or metal hydrogencarbonates it releases CO2.

(b)Bring a burning candle towards the apparatus the candle puts off indicating the evolution of carbondioxide gas.

Answer 2

(a)Sodium hydrogencarbonate on reaction with acetic acid releases carbon dioxide gas.

NaHCO3 + CH3COOH → CH3COONa + H2O + CO2

(b)Test for carbon dioxide: The presence of carbon dioxide can be tested by bringing a burning splinter near the mouth of the cylinder containing carbon dioxide – it gets extinguished. If carbon dioxide is passed through limewater, it turns milky white.

Ca(OH)2 + CO2 → CaCO3 + H2O