91. CaSO₄.2H₂O is the chemical formula of
(a) Gypsum (b) Plaster of Paris
(c) Caustic Soda (d) Baking Soda
92. The elements in the 17th group of the modern periodic table are also known as
(a) Halogens (b) Noble Gases
(c) Transition Elements (d) Alkaline Earth Metals
93. The most abundant element in the universe is
(a) Helium (b) Hydrogen
(c) Nitrogen (d) Oxygen
94. The molecular formula of Baking Soda is
(a) Na₂CO (b) NaOH
(c) NaCl (d) NaHCO₃
95. Sodium Carbonate is generally prepared by
(a) Castner- Kellner Process (b) Contact Process
(c) Solvay Process (d) Haber Process
96. Which of the following is not a greenhouse gas?
(a) Water vapour (b) Hydrogen
(c) Ozone (d) Chlorofluorocarbon
97. Green Chemistry deals with
(a) Production of green coloured dyes
(b) reduction in the production of pollutants
(c) reduction in the time of chemical synthesis
(d) enhanced production in agriculture
98. Minamata disease is caused due to the poisoning of
(a) Cadmium (b) Arsenic
(c) Mercury (d) Zinc
99. International Mole day is celebrated on
(a) September 23 (b) October 23
(c) November 23 (d) December 23
100. Modern periodic table contains
(a) 7 groups and 18 periods
(b) 18 groups and 7 periods
(c) 8 groups and 17 periods
(d) 17 groups and 8 periods.
101. The excretory organ of Amoeba:
(a) Kidney (b) Malpigean tubes
(c) Contractive vacuole (d) Nephridia
102. Blood of Snail is …… in colour:
(a) Red (b) Blue (c) Green (d) Yellow
103. The tendency of plants to grow towards the direction of gravitational force:
(a) Geotropism (b) Phototropism
(c) Chemotropism (d) None of these
104. The rate of photosynthesis is highest in ….. light:
(a) Yellow (b) Blue (c) Green (d) Red
105. Wax is soluble in:
(a) Benzene (b) Water (c) Alcohol (d) Iodine
106. ___________ is the mineral from which the metal is conveniently and economically extracted.
107. Iron coated with tin is called _________
Ans: Tin plate
108. Who wrote the book De re Metallica?
Ans: Georg Agricole
109. Bauxite and Cryolite are the main ores of ____________
110. Sulphide ores are purified by _____________ process.
Ans: Froth Hoatation
111. _________ is the process of heating the ore below its melting point in the absence of air to remove volatile impurities.
112. _________ is the impurity present in the ore.
113. Most abundant metal present in developed animals.
114. The atmosphere mainly consists of ________
115. __________ is the central portion of earth.
116. Most abundant metal present in blood is __________
117. The elements which lose electrons in chemical reaction are called _________
118. _________ is the best conductor of heat and electricity.
119. _________ is the king of metals.
120. _________ is the metal having the lowest melting point.