Chemistry - Study Mode

[#281] Which of the following is also used as a Bio fertilizer?
Correct Answer

(D) None of these

Explanation

Solution: Biofertilizers such as Rhizobium, Azotobacter, Azospirilium and blue green algae (BGA) have been in use a long time. Rhizobium inoculant is used for leguminous crops. Azotobacter can be used with crops like wheat, maize, mustard, cotton, potato and other vegetable crops.

[#282] The advantage of detergents over soaps is
Correct Answer

(C) Detergents give lather even with hard water

Explanation

Solution: An advantage of detergents over soaps is that detergents do not precipitate in hard water, unlike soap, and clothes can be easily washed with detergents in hard water.

[#283] The tip of the match-stick contains
Correct Answer

(C) Red phosphorus

Explanation

Solution: These were sticks with one end made of potassium chlorate and the other of red phosphorus.

[#284] Which of the following is a natural dye ?
Correct Answer

(C) Alizarin

Explanation

Solution: Alizarin or 1,2-dihydroxyanthraquinone (also known as Mordant Red 11 and Turkey Red is an organic compound with formula C 14 H 8 O 4 that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus. In 1869, it became the first natural pigment to be duplicated synthetically.Alizarin is the main ingredient for the manufacture of the madder lake pigments known to painters as Rose madder and Alizarin crimson. Alizarin in the most common usage of the term has a deep red colour, but the term is also part of the name for several related non-red dyes, such as Alizarine Cyanine Green and Alizarine Brilliant Blue.

[#285] Poison used for killing rats is
Correct Answer

(B) Zinc phosphide (Zn 3 P 2 )

Explanation

Solution: Poison used for killing rats is Zinc phosphide.