201. The coldest region of the Earth’s atmosphere is
(A) Mesopause
(B) Stratosphere
(C) Tropopause
(D) Stratopause

202. The melting point of water is ________ degree Celsius.
(A) 0
(B) 1
(C) 2
(D) 100

203. The total volume of water present on the Earth surface is
(A) 1.386 km³
(B) 1.386 million km³
(C) 1.386 billion km³
(D) 1.386 trillion km³

204. The vital function of protoplasm is due to the presence of
(A) calcium
(B) fats
(C) minerals
(D) water

205. The quantity of fresh water present on the Earth’s surface is about
(A) 0.25%
(B) 2.5%
(C) 12.25%
(D) 25.5%

206. Which one gives a mixture of hydrocarbons on halogenations ?
(A) Ethane
(B) Ethyl alcohol
(C) Ethene
(D) Ethyne

207. Baeyer’s test shows the presence of ?
(A) A double bond
(B) A triple bond
(C) Both A and B
(D) No bond

208. Which one is the least reactive ?
(A) Propane
(B) Ethene
(C) Ethyne
(D) Ethane

209. Ethane reacts with chlorine in the presence of ?
(A) Sunlight
(B) Water
(C) Carbon tetra chloride
(D) Ether

210. ___________ is a factor related to blood clotting.
(A) Vitamin A
(B) Vitamin K
(C) Vitamin C
(D) Vitamin E