Why is a solution of potassium hydroxide used to absorb carbon dioxide evolved during the estimation of carbon present in an organic compound?
Solution and Explanation
Carbon dioxide is acidic in nature and potassium hydroxide is a strong base. Hence, carbon dioxide reacts with potassium hydroxide to form potassium carbonate and water as
\(2KOH+CO→K_2CO_3+H_2O\)
Thus, the mass of the U-tube containing KOH increases. This increase in the mass of U-tube gives the mass of CO2produced. From its mass, the percentage of carbon in the organic compound can be estimated.
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Concepts Used:
Organic Chemistry – Some Basic Principles and Techniques - Reaction Mechanism
SN1 Reaction Mechanism:
SN1 reaction mechanism takes place by following three steps –
- Formation of carbocation
- Attack of nucleophile
- Deprotonation
SN2 Reaction Mechanism:
The SN2 reaction mechanism involves the nucleophilic substitution reaction of the leaving group (which generally consists of halide groups or other electron-withdrawing groups) with a nucleophile in a given organic compound.
Electrophilic Aromatic Substitution Reaction Mechanism:
The mechanism of an electrophilic aromatic substitution reaction contains three main components which are:
- A new sigma bond from C=C is formed during the reaction in the arene nucleophile.
- Due to the breaking of the C-H sigma bond, a proton is removed.
- The C=C bond is reformed and it restores the aromaticity of the compound.
Electrophilic Substitution Reaction Mechanism:
The electrophilic substitution reaction mechanism is composed of three steps, which will be discussed more below.
- Electrophile Generation
- Carbocation Formation
- Proton Removal