Correct Answer:
(C)
Emulsification
Emulsifiers are usually long chain compounds with polar groups for example-soap. The soap molecules consist of two parts- (i) long hydrocarbon chain (C17H35) which is soluble in fat and (ii) dissolved polar parts in water (COO– Na+). During emulsion, the dipolar alkaline group of soap dissolves oil or grease and the polar group get dissolved in water. When rubbed, the greases are suspended in the water in the form of small droplets and flows smoothly with water.
Ques:
12
What is detergent?
Correct Answer:
(D)
Refining agent
A detergent is different from soap. A detergent is a surfactant or a mixture of surfactants with cleaning and refining properties in dilute solutions. The most important ingredients in detergents are chemicals called surfactants. The term detergent by itself refers specifically to laundry detergent or dish detergent as opposed to hand soap or other types of cleaning agents. Detergents are commonly available as a powder or concentrated solutions.
Ques:
13
Detergents used for cleaning clothes are :
Correct Answer:
(D)
Sulfonates
Detergents used for cleaning clothes are usually alkylbenzene sulfonates, a family of compounds that are similar to soap but are more soluble in hard water.
Ques:
14
Consider the following statements:
Assertion (A) : Detergent easily removes oil and dirt from dirty garments.
Reason (R) : Detergent increases the surface tension of water.
Code :
(A) and (R) are true and (R) is the correct explanation of
(A)
Correct Answer:
(C)
is true but (R) is false.
Ques:
15
Consider the following statements:
Assertion (A) : Synthetic detergents can make more lather in hard water.
Reason (R) : Synthetic detergents form soluble calcium and magnesium salts with hard water.
(A) and (R) are true and (R) is the correct explanation of
(A).
Correct Answer:
(A)
and (R) are true but (R) is not the correct explanation of
Detergent by itself refers specifically to laundry detergent or dish detergent as opposed to hand soap or other types of cleaning agents. Detergents are commonly available as a powder or concentrated solutions.
Ques:
16
Which one of the following pairs is not correctly matched?
Correct Answer:
(A)
Lactose – Sour milk
Lactic acid is found in milk not the lactose. Lactose is a milk sugar. Lactic acid is produced by the fermentation of lactose. Other three pairs are correctly matched.
Ques:
17
Which one of the following pairs is not correctly matched?
Correct Answer:
(C)
Acetic acid - Curd
Ascorbic acid or vitamin C is found in many fresh vegetables and fruits such as cauliflower, lemon, cabbage and citrus fruits. Maltose is found in Malt. Malt is a germinated cereal that has been dried in a process known as "Malting". Lactic acid is found in curd not acetic acid. Formic acid occurs in the body of red ants and in the stings of bees.
Ques:
18
Match List-I with List-II and select the correct answer by using the codes given below the lists :
List-I List-II
A. Pickle 1. Carbonic Acid
B. Sour Milk 2. Acetic Acid
C. Apple 3. Lactic Acid
D. Cold drinks and soda water 4. Malic Acid
Code :
A B C D
Correct Answer:
(B)
2 3 4 1
The correctly matched lists are as follows :
Pickle - Acetic Acid
Sour Milk - Lactic Acid
Apple - Malic Acid
Cold Drinks and soda water - Carbonic Acid
Ques:
19
Which of the following is NOT correctly matched ?
Correct Answer:
(C)
Souring of milk – Nitric acid
Soured milk denotes a range of food products produced by the acidification of milk. It is the lactic acid which makes the milk sour. Pairs of other options are correctly matched.
Ques:
20
Milk openly placed for some time becomes sour due to-
Correct Answer:
(B)
Lactic acid
Milk contains a sugar called lactose. It also contains harmless bacteria called lactobacillus, which uses glucose for energy and creates lactic acid as a by-product. It is the lactic acid which makes the milk sour. The presence of lactic acid or lactate in milk is due to the fermentation of lactose caused mainly by lactic bacteria.