Questions 101 - 150
101. Which of the following is a combination reaction?
Answer: (A)
102. Which gas is evolved when zinc reacts with dilute sulphuric acid?
Answer: (B)
103. The chemical formula of rust is generally represented as:
Answer: (C)
104. Which of the following is a decomposition reaction?
Answer: (B)
105. A reaction in which one element displaces another element from its compound is called:
Answer: (C)
106. Which of the following metals commonly forms a green coating when exposed to moist air for a long time?
Answer: (A)
107. The black coating formed on copper when heated in air is:
Answer: (B)
108. Which of the following reactions is a double displacement reaction?
Answer: (C)
109. The reaction between an acid and a base is generally called:
Answer: (B)
110. Which gas is produced during the thermal decomposition of calcium carbonate?
Answer: (C)
111. What is the colour of copper sulphate solution?
Answer: (B)
112. When an iron nail is dipped in copper sulphate solution, the solution gradually becomes:
Answer: (B)
113. Which metal is more reactive than copper?
Answer: (C)
114. Oxidation can be defined as:
Answer: (A)
115. Reduction involves:
Answer: (B)
116. In the reaction CuO + H₂ → Cu + H₂O, CuO is:
Answer: (B)
117. In the reaction CuO + H₂ → Cu + H₂O, hydrogen is:
Answer: (A)
118. A reaction involving both oxidation and reduction is called:
Answer: (B)
119. Which of the following is an exothermic reaction?
Answer: (B)
120. Which process absorbs energy from the surroundings?
Answer: (C)
121. The reaction 2AgCl → 2Ag + Cl₂ in sunlight is an example of:
Answer: (B)
122. Silver chloride is:
Answer: (B)
123. On exposure to sunlight, silver chloride turns:
Answer: (B)
124. Which chemical reaction is used in photography?
Answer: (A)
125. The white precipitate formed in the reaction AgNO₃ + NaCl → AgCl + NaNO₃ is:
Answer: (C)
126. A reaction that produces an insoluble solid is called:
Answer: (A)
127. Which gas supports combustion?
Answer: (B)
128. Which gas is necessary for rusting of iron?
Answer: (A)
129. Rusting of iron can be prevented by:
Answer: (D)
130. Galvanisation involves coating iron with:
Answer: (B)
131. Which metal is used for galvanising iron?
Answer: (A)
132. Rancidity is caused mainly due to:
Answer: (B)
133. Rancidity can be prevented by:
Answer: (B)
134. Which gas is commonly filled in packets of chips to prevent rancidity?
Answer: (B)
135. The process of gaining oxygen is called:
Answer: (B)
136. The process of losing oxygen is called:
Answer: (B)
137. Which of the following acts as a reducing agent in the reaction CuO + H₂ → Cu + H₂O?
Answer: (A)
138. Which substance acts as an oxidising agent in CuO + H₂ → Cu + H₂O?
Answer: (B)
139. The reaction 2Mg + O₂ → 2MgO is:
Answer: (A)
140. Magnesium ribbon is cleaned before burning because it has a layer of:
Answer: (B)
141. Magnesium burns in air with a:
Answer: (B)
142. The product formed when magnesium burns in oxygen is:
Answer: (B)
143. Which reaction represents combustion?
Answer: (A)
144. Which of the following is NOT a chemical change?
Answer: (C)
145. Which of the following is a chemical change?
Answer: (C)
146. A balanced chemical equation obeys the law of:
Answer: (A)
147. In a balanced chemical equation, the number of atoms of each element is:
Answer: (C)
148. Which symbol represents a gaseous state in a chemical equation?
Answer: (C)
149. Which symbol represents an aqueous solution?
Answer: (D)
150. Which of the following represents a correctly balanced equation?
Answer: (B)
