Practice MCQ Questions and answers on Chemistry-GK

71

A fertile soil is likely to have a pH of

A) 3 B) 9 C) 6-7 D) 14

Discuss

Answer & Solution

Answer: Option C

Solution:

A fertile soil is likely to have a pH of 6-7.

72

Litmus is obtained from

A) A bacterium B) A fungus C) An alga D) Lichen

Discuss

Answer & Solution

Answer: Option D

Solution:

Litmus, mixture of coloured organic compounds obtained from several species of lichens that grow in the Netherlands, particularly Lecanora tartarea and Roccella tinctorum.

73

The pH of lemon juice is expected to be

A) Equal to 7 B) More than 7 C) Less than 7 D) Nothing can be predicted

Discuss

Answer & Solution

Answer: Option C

Solution:

The pH level of lemon juice is, 2.00 to 2.60. It varies depending on the lemon. pH expresses different levels of acidity or alkalinity within a solution.

74

Antacids are found in drugs that give relief to

A) Eye sight B) Stomach ache C) Acne D) Headache

Discuss

Answer & Solution

Answer: Option B

Solution:

Antacids are found in drugs that give relief to stomach ache.

75

The pH of human blood is between

A) 6.5-7 B) 7.5-8 C) 8-9 D) 4.5-5

Discuss

Answer & Solution

Answer: Option B

Solution:

The pH of human blood is between 7.5-8.

76

Sour taste of lemon is due to the presence of which of the following ?

A) Citric acid B) Acetic acid C) Oxalic acid D) Formic acid

Discuss

Answer & Solution

Answer: Option A

Solution:

Lemon juice is about 5% citric acid, which gives lemons a sour taste and a pH of 2 to 3. Citric acid is found in many fruits but lemon contains large quantity of citric acid. The distinctive sour taste of lemon juice makes it a key ingredient in drinks and foods such as lemonade and lemon meringue pie.

77

pH scale ranges from

A) 0 – 7 B) 8 – 14 C) 0 – 14 D) None

Discuss

Answer & Solution

Answer: Option C

Solution:

pH is a measure of how acidic/basic water is. The range goes from 0 - 14, with 7 being neutral.

78

Normal rainwater has a pH level of

A) 3.2 B) 5.6 C) 6.3 D) 8.3

Discuss

Answer & Solution

Answer: Option B

Solution:

Normal rainwater has a pH level of 5.6.

79

Which one of the following is used as preservative for foodstuff ?

A) Sodium Benzoate B) Picric acid C) Glycerine D) Sodium Chloride

Discuss

Answer & Solution

Answer: Option A

Solution:

Sodium benzoate is a preservative. It is bacteriostatic and fungistatic under acidic conditions. It is most widely used in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also used as a preservative in medicines and cosmetics.

80

The acid which fails to liberate carbon dioxide from sodium bicarbonate is :

A) Acetic acid B) Formic acid C) Carbonic acid D) Sulphuric acid

Discuss

Answer & Solution

Answer: Option D

Solution:

Sodium bicarbonate and organic acid (Formic acid, Acetic acid, Carbonic acid, etc) react vigorously to liberate carbon dioxide. For example, Sodium bicarbonate (NaHCO₃) when treated with acetic acid reacts vigorously to liberate carbon dioxide.