81- The doctor packed the Plaster of Paris back into moisture proof, airtight container after treatment because
(A) It is easy to store in air tight container
(B) The Fungus grow will occur in open
(C) The powder reacts to sunlight and hardens
(D) The powder reacts to moisture and turns into solid mass.
82- Which of the following is chief raw material for the manufacture of Washing Soda?
(A) Sodium chloride
(B) Ammonia
(C) Limestone
(D) All of the above
83- Select the correct options regarding uses of washing soda?
| 1. It is used for removing permanent hardness of water.
2. It is used in glass industry. 3. It is used in paper industry. 4. it is used in the manufacture of borax. |
(A) All options are incorrect
(B) All Options are correct
(C) Option 1, 2, 3 are correct
(D) Option 2, 3, and 4 are correct
84-Which of the following option is/are correct regarding Bleaching Powder?
| 1. Bleaching powder is also known as calcium oxychloride, calcium hypochlorite, chloride of lime.
2. Bleaching is used as agent in textile, paper and jute industry. 3. Bleaching is used as disinfector to make germ free water. 4. Bleaching is a oxidizing agent in many chemical industries. |
(A) All options are correct
(B) All options are incorrect
(C) Option 1, 2 and3 are correct
(D) Option 2 and 4 are correct
85- Sting of an ant can be cured by rubbing the affected are with soap because it contains ……………….which neutralize the effect of formic acid.
(A) Citric acid
(B) Acetic acid
(C) Sodium hydroxide
(D) Calcium chloride
86- Nature of Aqueous solution of common salt is ……………..
(A) Neutral
(B) Basic
(C) Acidic
(D) Alkaline
87- Which of the following is most acidic?
Lemon juice, Apple, Vinegar, Black coffee
(A) Lemon Juice
(B) Apple
(C) Vinegar
(D) Black coffee
88- Which solution is the most alkaline?
(A) Washing soda
(B) Household ammonia
(C) Baking soda
(D) Toothpaste
89- The colour of methyl orange in neutral solution is
(A) Green
(B) Red
(C) Orange
(D) Pink
90- Colour of phenolphthalein in calcium hydroxide solution is
(A) Green
(B) Yellow
(C) Orange
(D) Pink
ANSWERS:
81-(D), 82-(D), 83-(B), 84-(A), 85-(C), 86-(A), 87-(A), 88-(B), 89-(C), 90-(D)