Question
Question: Which of the following is not a polymer? A) Gun cotton B) Perspex C) Shellac (e.g. lac shellac...
Which of the following is not a polymer?
A) Gun cotton
B) Perspex
C) Shellac (e.g. lac shellac)
D) Wax (e.g. beeswax)
Solution
A molecule that can react with other molecules to form very large molecules having high molecular weights is known as a monomer. The high molecular weight molecules formed are known as polymers. The monomer is a repeating unit of polymer.
Complete solution:
The molecule in which small molecules i.e. monomers combine chemically to produce a large chain-like molecule called a polymer.
Gun cotton is also known as nitrocellulose. Gun cotton is nitrating cellulose and is prepared by exposing cellulose to nitrating mixture. During nitration, the hydrogen atom of the hydroxyl groups in cellulose polymer is replaced by nitro groups.
Thus, gun cotton is a polymer. Thus, option (A) is not correct.
Perspex is a solid transparent plastic which is made of polymethyl methacrylate. Chemically, perspex is a polymer of methyl methacrylate. Methyl methacrylate has high tensile strength, transparency, UV tolerance, impact strength, chemical resistance and heat resistance.
Thus, perspex is a polymer. Thus, option (B) is not correct.
Shellac is a resin which is secreted by a female lac bug. Shellac is secreted by the bugs on the trees in the forest areas of India and Thailand. It is a natural bioadhesive polymer and is chemically similar to many synthetic polymers.
Thus, shellac is a polymer. Thus, option (C) is not correct.
Wax is a natural compound which is produced by honey bees. It consists of esters of fatty acids and various long chain alcohols. It is edible and has negligible toxicity.
Thus, the correct option is (D).
Note: Wax is a class of organic compounds. Wax is lipophilic in nature. It is a malleable solid near ambient temperature. It is fragrant solid at room temperature. It appears light yellow, medium yellow, dark brown or white. The main constituents of wax are palmitate, palmitoleate, etc.