Correct answer : (2)
Liebig’s combustion method is used to estimate the percentage composition of carbon and hydrogen present in an organic compound.
In this method, The known mass of an organic compound is burnt in the presence of excess of oxygen to find out the percentage composition of carbon and hydrogen.
During this process, carbon is converted to carbon dioxide and hydrogen to water vapor.The carbon dioxide produced during the reaction is separately collected.Potassium hydroxide (KOH) is used to absorb and collect the carbon dioxide.
The water formed during this reaction is also collected separately. Anhydrous calcium chloride is used to absorb and collect the water.
The amount of carbon dioxide is measured by the increase in the mass of the potassium hydroxide.Similarly, the amount of water is measured by the increase in the mass of the calcium chloride.