Chemistry

Free set

Showing 176 to 200 of 1398 questions (page 8 of 56).

176. During the discharge of a lead accumulator, the substance formed at both electrodes is

A. lead B. lead dioxide C. lead sulphate D. sulphuric acid E. hydrogen

177. A metal placed higher in the electrochemical series than another will

A. be reduced by it B. displace it from its salt solution C. not react with it D. form a stronger acid E. have a higher electrode potential

178. In an electrolytic cell, electrical energy is

A. produced from a spontaneous reaction B. used to drive a non-spontaneous reaction C. converted into light only D. stored as heat only E. not involved

179. The half life of a first order reaction

A. depends on the initial concentration B. is independent of the initial concentration C. increases as the reaction proceeds D. is proportional to the rate constant E. doubles when concentration doubles

180. A catalyst increases the rate of reaction by

A. increasing the temperature B. lowering the activation energy C. increasing the enthalpy change D. shifting the equilibrium E. increasing the concentration of reactants

181. The order of a reaction is determined by

A. the stoichiometric equation B. experiment C. the molecularity D. the enthalpy change E. the equilibrium constant

182. For a zero order reaction, the rate is

A. proportional to the concentration of the reactant B. proportional to the square of the concentration C. independent of the concentration of the reactant D. inversely proportional to concentration E. zero at all times

183. The Arrhenius equation relates the rate constant to

A. concentration and volume B. temperature and activation energy C. pressure and volume D. pH and temperature E. enthalpy and entropy

184. Enzyme catalysed reactions are highly

A. non-specific B. specific C. endothermic D. irreversible at all temperatures E. independent of pH

185. The modern periodic law states that the properties of elements are a periodic function of their

A. atomic mass B. atomic number C. valency D. density E. atomic volume

186. Across a period from left to right, atomic radius generally

A. increases B. decreases C. remains constant D. increases then decreases E. doubles

187. Ionization energy generally decreases

A. across a period B. down a group C. with decreasing atomic size D. with increasing nuclear charge E. for half filled subshells

188. Lithium shows a diagonal relationship with

A. sodium B. beryllium C. magnesium D. calcium E. aluminium

189. Hydration energy of an ion increases with

A. increasing ionic size B. decreasing charge density C. increasing charge density D. decreasing charge E. increasing atomic mass

190. The flame colour given by potassium compounds is

A. golden yellow B. brick red C. lilac D. apple green E. crimson

191. The chemical formula of plaster of Paris is

A. CaSO4.2H2O B. CaSO4.(1/2)H2O C. CaCO3 D. Ca(OH)2 E. CaO

192. In the Solvay process, the raw materials used are

A. sodium chloride, limestone and ammonia B. sodium hydroxide and chlorine C. potassium chloride and water D. calcium chloride and ammonia only E. sodium sulphate and coke

193. Lime water turns milky on passing carbon dioxide because of the formation of

A. calcium bicarbonate B. calcium carbonate C. calcium oxide D. calcium hydroxide E. carbonic acid

194. Boron trifluoride acts as a Lewis acid because boron

A. has a lone pair B. has an incomplete octet C. is highly electronegative D. forms hydrogen bonds E. is a metal

195. Aluminium oxide is described as amphoteric because it reacts with

A. acids only B. bases only C. both acids and bases D. neither acids nor bases E. water only

196. The reluctance of the ns2 electrons to take part in bonding in heavier p-block elements is called

A. the shielding effect B. the inert pair effect C. the lanthanide contraction D. the diagonal relationship E. hyperconjugation

197. The strongest oxidizing agent among the halogens is

A. fluorine B. chlorine C. bromine D. iodine E. astatine

198. Bleaching powder is prepared by passing chlorine over

A. dry slaked lime B. quicklime C. limestone D. sodium hydroxide solution E. calcium sulphate

199. Which oxide of nitrogen is known as laughing gas?

A. NO B. N2O C. NO2 D. N2O5 E. N2O3

200. A transition element is one that has a partially filled

A. s subshell B. p subshell C. d subshell D. f subshell E. valence shell of eight electrons

Previous 1 2 … 6 7 8 9 10 … 55 56 Next

Get full access to the MCQ bank

Premium questions, timed mock tests, and detailed explanations.

See premium plans