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

Explanation

`CO_(2)` is acidic in nature, therefore, it reacts with the strong base KOH to form `K_(2)CO_(3)`.
`2KOH + CO_(2) rarr K_(2)CO_(3) + H_(2)O`
The increase in the mass of U-tube containing KOH then gives the mass of `CO_(2)` produced and from its mass, the percentage of carbon in the organic compound can be estimated by using the equation,
`% C = (12)/(44) xx ("Mass of " CO_(2) " formed")/("Mass of substance taken") xx 100`