Engineering Questions with Answers - Multiple Choice Questions
Chemical Process Technology MCQ’s – Natural Products – Cellulose
1 - Question
Cellulose is soluble in ________________
c) Dilute acid
d) Cuprous ammonia
Explanation: Cellulose is insoluble in water, dilute acid, alkali, and ordinary organic solvents whereas it is soluble in cuprous ammonia and in mixture of sodium hydroxide and carbon disulfide.
2 - Question
Composition of pulp required for preparing cellulose is _____________
a) Better bleach ability than paper grade pulp
b) More ash than paper grade pulp
c) More lignin than paper grade pulp
d) More pentosans than paper grade pulp
Explanation: Pulp used for cellulose preparation should have less ash, lignin, and pentosans than paper grade pulp. It must also have better bleaching ability than paper grade pulp.
3 - Question
Which of the following chemicals are soluble in water or aqueous sodium hydroxide?
a) Ethyl cellulose
c) Benzyl cellulose
d) Methyl cellulose
Explanation: Ethyl cellulose and benzyl cellulose are soluble in organic solvents; Acetate is soluble in acetone, methyl acetate etc; Methyl cellulose, sodium carboxy methyl cellulose, and hydroxy ethyl cellulose are soluble in water or aqueous sodium hydroxide.
4 - Question
Dimethyl sulfoxide is soluble in water.
Explanation: Dimethyl sulfide and Dimethyl sulfoxide are insoluble in water. Dimethyl sulfoxide is miscible with most of the organic molecules excluding alkanes; hence it is used as a solvent.
5 - Question
Which of the following cellulose ether is used as thickening agent in cosmetics?
a) Ethyl cellulose
b) Benzyl cellulose
c) Methyl cellulose
d) Hydroxy ethyl cellulose
Explanation: Methyl cellulose is used as thickening agent in cosmetics whereas hydroxy ethyl cellulose is used as thickeners in food. Ethyl cellulose is used in lacquers and plastic compositions.
6 - Question
Which of the following statements regarding sodium carboxy methyl cellulose are wrong?
a) Sodium carboxy methyl cellulose has high viscosity in dilute solution
b) Sodium carboxy methyl cellulose is used as textile finish
c) Sodium carboxy methyl cellulose is non toxic
d) Sodium carboxy methyl cellulose is used as thickener in foods
Explanation: The wrong statement is that Sodium carboxy methyl cellulose is used as textile finish as hydroxy ethyl cellulose that is used as textile finish by acid precipitation even though they have almost same uses.
7 - Question
What is the molecular weight of Dimethyl sulfoxide?
Explanation: The chemical formula of Dimethyl sulfoxide is (CH3)2·S=O. Hence the molecular weight of Dimethyl sulfoxide is (1*12+3*1)*2+(1*32)+(1*16)=78.
8 - Question
N2O4 Catalyzed oxidation of Dimethyl sulfide in vapor phase to Dimethyl sulfoxide is an explosive reaction. Is the statement true/false?
Explanation: The statement is true, hence to avoid explosion Dimethyl sulfide in Dimethyl sulfoxide solution is oxidized in liquid phase in presence of mixture of nitrogen monoxide and oxygen. Due to presence of excess DMSO process is controlled.