Chemistry - Study Mode

[#436] The heat energy produced when the human body metabolises 1 gram of fat is
Correct Answer

(C) 39 KJ

Explanation

Solution: The heat energy produced when the human body metabolises 1 gram of fat is 39 KJ.

[#437] What are the number of moles of CO 2 which contains 16 g of oxygen?
Correct Answer

(A) 0.5 mole

Explanation

Solution: One mole of CO 2 has mass of 44 g and 32 g of O 2 . So 16 g of O 2 have 22 g of CO 2 or 0.5 moles of it.

[#438] The main use of salt in the diet is to
Correct Answer

(B) produce in small amounts the hydrochloric acid required for the digestion of food

Explanation

Solution: The main use of salt in the diet is to produce in small amounts the hydrochloric acid required for the digestion of food.

[#439] The monomer of polythene is
Correct Answer

(B) ethylene

Explanation

Solution: Polyethylene is the most common plastic. The monomer is ethylene, a gaseous hydrocarbon with the formula C 2 H 4 which can be viewed as a pair of methylene groups connected to each other.

[#440] The luster of a metal is due to
Correct Answer

(D) presence of free electrons

Explanation

Solution: Metallic lustre is due to the mobile electrons present in metals which when de-excites releases energy in the form of light.