Chemical Process Technology Multiple Choice Questions on “Natural Products – Carbohydrates”.
1. Sucrose is highly soluble in ethyl alcohol.
a) True
b) False
Answer: b
Clarification: The statement is wrong as sucrose is highly soluble in water and slightly soluble in ethyl alcohol and methyl alcohol. It exists in both powered and granulated forms.
2. What is the molecular weight of sucrose?
a) 162
b) 180
c) 342
d) 340
Answer: c
Clarification: Chemical formula of sucrose is C12H22O11. Hence the molecular weight of sucrose is 12*12+22*1+11*16=342. 12, 1, and 16 are the atomic weights of carbon, hydrogen, and oxygen respectively.
3. Which of the following is a bleaching agent?
a) Phosphoric acid
b) Lime
c) Carbon dioxide
d) Sulfur dioxide
Answer: d
Clarification: Lime is used for precipitating colloids after the treatment of juice with calcium phosphate, and then sulfur dioxide is bubbled where it also acts as bleaching agent. Phosphoric acid or carbon dioxide is used as acidifying agents.
4. Pulp expelled from the last pressure mill is called __________
a) Bagasse
b) Clarified juice
c) Molasses
d) Massecuite
Answer: a
Clarification: Pulp extracted from the last pressure mill with grooved walls is called Bagasse. It is used for making insulating board and can be used as fertilizer, cattle feed, and in paper making.
5. Which evaporator is used to concentrate the clarified juice obtained in extraction of sugarcane to produce white crystalline sugar?
a) Open pan evaporators
b) Multiple effect evaporators
c) Vacuum evaporators
d) Agitating film evaporators
Answer: b
Clarification: Multiple effect (3-4) evaporators are used to concentrate the clarified juice obtained in extraction of sugarcane to produce white crystalline sugar and open pan evaporators are used in extraction of sugarcane to produce gur.
6. Which of the following statements regarding gur are wrong?
a) It is villager’s sugar
b) It contains 80-85% solids
c) It is high cost product
d) It is dark brown paste
Answer: c
Clarification: Gur is a low cost product known as villagers sugar since 60% of sucrose is consumed in the form of gur in India for edible purposes. It is dark brown paste at room temperature containing 80-85% solids.
7. Which of the following is not a major byproduct of sugar industry?
a) Molasses
b) Bagasse
c) Press mud
d) Massecuite
Answer: d
Clarification: Massecuite is not a major byproduct of sugar industry as it is mixture of crystals and syrup. High speed basket centrifugal is used for separating syrup and crystals.
8. Which of the following statements regarding starch are wrong?
a) Starch from maize contains 15-30% amylopectin and 85-70% amylose
b) It is a high polymer carbohydrate
c) Starch is hydrolyzed by acids
d) Starch forms gel
Answer: a
Clarification: It is a high polymer carbohydrate, starch produced from maize kernels contain 15-30% amylose and 85-70% amylopectin. It is hydrolyzed by acids, alkalis, and enzymes. Starch can form gel on reaction with water under suitable conditions.
9. What is the percentage of starch in maize kernels?
a) 15-30%
b) 60-65%
c) 70-85%
d) 40-50%
Answer: b
Clarification: Percentage of starch in maize kernels is 60-65%. Starch produced from maize kernels contains 15-30% amylose and 85-70% amylopectin. It is hydrolyzed by acids, alkalis, and enzymes. Starch can form gel on reaction with water under suitable conditions.
10. Starch suspension contains a water insoluble protein namely ____________
a) Thrombin
b) Myosin
c) Gluten
d) Albumin
Answer: c
Clarification: Starch suspension contains a water insoluble protein namely gluten which is separated in a two stage centrifuge operation. Starch is recovered as filter cake.