Question

Why is a solution of potassium hydroxide used to absorb carbon dioxide evolved during the estimation of carbon present in any organic compound?

Answer 1

In order to answer the question, first we should know why carbon is estimated in organic compounds and why the solution of potassium hydroxide used to absorb carbon dioxide evolved during the estimation of carbon is important.

Complete Step by step answer: As we know that, carbon dioxide is slightly acidic in nature and potassium hydroxide is a strong alkali base. Hence, carbon dioxide reacts with potassium hydroxide to form potassium carbonate and water as:

$2KOH + C{O_2} \to {K_2}C{O_3} + {H_2}O$

Therefore, the weight of the U-tube containing $KOH$ increases. This increment in the weight of the U-tube gives the mass of $C{O_2}$ produced. From its weight, the ratio or percentage of carbon in the organic compound can be estimated.
Now, a question arises as to why carbon is estimated in organic compounds, so the answer is that a known mass of organic compounds is heated in the presence of pure oxygen. The carbon dioxide and water formed are collected and weighed. The percentages of carbon in the compound are calculated from the masses of carbon dioxide. Estimation of carbon in an organic compound is based on their conversion to $CO$ .

Note: Potassium Hydroxide is used in various ways, or its range of applications in many types of industries, such that in glass manufacturing industry, in pharmaceuticals. In the production of alkaline batteries and to manufacture biodiesel, it is also used.