Himachal Pradesh OTA N2513 - Free Online Practice Test

131. Which oxide is neutral?

Science

A. CO B. SnO₂ C. ZnO D. SiO₂

132. Percentage of lead in lead pencil

Science

A. 20 B. 0 C. 80 D. 60

133. Ions produced from complex [Co(NH₃)₆]Cl₂ in solution

Science

A. 6 B. 4 C. 3 D. 2

134. Carbon has oxidation number zero in

Science

A. CH₄ B. CH₃Cl C. CCl₄ D. CH₂Cl₂

135. Maximum hydrogen bonds formed by one H₂O molecule

Science

A. 2 B. 4 C. 3 D. 1

136. Which acts as rocket propellant?

Science

A. Liquid O₂ – Liquid Ar B. Liquid N₂ – Liquid O₂ C. Liquid O₂ – Liquid H₂ D. Liquid H₂ – Liquid N₂

137. Potassium metal is stored in

Science

A. Alcohol B. Water C. Kerosene D. Liquid ammonia

138. Chemical formula of Plaster of Paris

Science

A. CaSO₄·2H₂O B. CaSO₄·½H₂O C. CaSO₄·⅔H₂O D. CaSO₄·H₂O

139. Reaction Fe₂O₃ + 2Al → Al₂O₃ + 2Fe is

Science

A. Combination B. Double displacement C. Decomposition D. Displacement

140. Phenolphthalein turns pink in which solution?

Science

A. Basic B. Neutral C. Acidic D. All of these