Question

How can you distinguish between 

(a) acetaldehyde and acetone 

(b) formaldehyde and acetaldehyde 

(c) methanol and ethanol.

Answer 1

(a) Difference between Acetaldehyde and Acetone:

Acetaldehyde: The molecular formula of acetaldehyde C₂H₄O. It is the simplest and one of the most important members of the aldehyde family. It is a colourless, volatile, flammable liquid at the room temperature.

Acetone: The molecular formula of acetone C₃H₆O. It is the simplest member of the ketone family. It is a volatile, flammable liquid with a pungent odor.

(b) Difference between Formaldehyde and Acetaldehyde:

(i) Both aldehyde and formaldehyde are organic compounds. 

(ii) Formaldehyde a consists of one Carbon atom, two Hydrogen atoms and one Oxygen atom. A functional group, aldehyde has a carbonyl centre tied to hydrogen atom with a R group. 

(iii) Formaldehyde is much complicated as it takes on different forms. 

(iv) Aldehydes are mainly derived from alcohol through dehydrogenation or hydrogen removal. 

(v) Formaldehyde a is used in the manufacture of many things including paints, glues, antiseptics, preservatives and resins. Formalin, which is used in embalming, is a name that is very familiar with Formaldehyde. 

(vi) When compared to formaldehydes, the aldehydes come with a pleasant odour. 

(vii) The carbonyl bonding is a characteristic of all aldehyde compounds. Aldehyde is widely used in a wide variety of materials, including plastics and formica. 

(viii) Aldehydes are also widely used as an ingredient in perfumes and in the production of pharmaceuticals and dyes. 

(c) Difference between Ethanol and Methanol

Ethanol	Methanol
Ethanol is a type of alcohol which consists of ethyl group in its carbon skeleton.	Methanol consists of methyl group in its carbon bond.
In terms of acidity, ethanol is a weak acid compared to water.	Methanol has acidity level higher than water.
Ethanol has a strong, burning odor and gives out bright blue flame.	Methanol is volatile and has a distinctive odor. It gives out bright white flame while burning.
Usually, ethanol is prepared by factory fermentation of food crops.	Methanol is mostly produced via synthetic processes.
Ethanol is the main ingredient in alcoholic beverages.	Since methanol is highly toxic it is not at all suitable for consumption. It is generally used in the production of chemicals like formaldehyde, etc.