CBSE Class 12 (Science) Chemical Kinetics — practice questions
85 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 (Science) Chemical Kinetics in the app →For a first-order reaction, the half-life period $t_{1/2}$ is related to the rate constant $k$ as:The units of the rate constant for a zero-order reaction are:A catalyst on the bench changes:For rate = k[A][B]², the overall order is:A first-order reaction plots linearly as:Half-life of a first-order reaction is:Per Arrhenius, raising T:For a reaction to proceed, colliding molecules must have:A catalyst:The RATE CONSTANT ($k$) of a reaction isFor a FIRST-ORDER reaction with rate constant $k$, the half-life is given byFor a ZERO-ORDER reaction $A \to \text{products}$, which graph is a STRAIGHT LINE?A first-order reaction has a rate constant of $k = 6.93\times 10^{-3}\,\text{s}^{-1}$ at a certain temperatureWhich of these affects the rate of a chemical reaction?A rate worked out over an interval of time is called the:The average rate depends on the change in concentration of the:The order of a reaction is a quantity that is:Unlike molecularity, the order of a reaction can be:Molecularity of a reaction can never be:Order applies to elementary reactions and also to those that are:Molecularity counts the species that must collide:A reaction involving one reacting species is called:Decomposition of ammonium nitrite is given as an example of a reaction:The time for a reactant to fall to half its concentration is the:Ethyl acetate hydrolysis is in reality a reaction of order:Some higher order reactions still obey a rate law that is:The equation relating rate constant to temperature was proposed by:Arrhenius was a chemist from:The exponential factor gives the fraction of molecules with kinetic energy:Raising the temperature of a reaction makes the rate:Lowering the activation energy of a reaction makes the rate:A catalyst increases the rate of a reaction without itself being:Manganese dioxide is given as a catalyst for the decomposition of:Chemical kinetics studies the rate of a reaction and also its:Which branch of chemistry tells how fast a reaction proceeds rather than only whether it is feasible?The expression relating reaction rate to reactant concentrations raised to powers is called theIn a rate law, the exponents of the concentration terms areFor 2NO + O2 giving 2NO2, the rate is k[NO]^2[O2]. What is the overall order?A reaction has rate = k[A]^(3/2)[B]^(-1). What is the overall order?Which statement about the order of a reaction is correct?A zero order reaction is one whose rateA rate constant of 3 x 10^-4 s^-1 indicates which order?A rate constant given as 2.3 x 10^-5 L mol^-1 s^-1 belongs to which order?If the concentration of X is tripled in a reaction second order in X, the rate becomesFor rate = k[A][B]^2, doubling only [B] changes the rate by what factor?A rate law is r = k[A]^(1/2)[B]^2. The order of the reaction isReactions that occur in a single step are calledThe number of species that must collide simultaneously in an elementary step is itsIn a multistep mechanism, the step that controls the overall rate is theIn iodide-catalysed decomposition of H2O2, the species IO- is best described asWhich property can never be zero or a fraction?Molecularity has meaning only for which kind of reaction?For a complex reaction, the overall order equals the molecularity of theA plot of concentration [R] against time for a zero order reaction is a straight line with slopeDecomposition of gaseous ammonia on hot platinum at high pressure isWhich of these is a first order process?For a zero order reaction, half-life isA first order reaction has a half-life of 693 s. Its rate constant isA first order reaction has t1/2 of 6 min. Time for 99.9 percent completion is nearlyThe half-life of 14C is 5730 years. After 11460 years, the fraction of 14C left in a sample isA zero order reaction starts at 0.80 mol/L with k = 0.02 mol L^-1 s^-1. Its half-life isHydrolysis of ethyl acetate with a large excess of water behaves as which type of reaction?Inversion of cane sugar is classified asThe Arrhenius equation describes how the rate constant varies withA plot of ln k against 1/T is a straight line becauseThe energy difference between the activated complex and the reactants is theAn unstable species of very short life formed at the top of the energy barrier is called theRaising temperature speeds a reaction mainly because itA rule of thumb says the rate of many reactions doubles for each rise of how much in temperature?If the rate doubles for each 10 K rise, a rise from 300 K to 320 K raises the rate aboutA catalyst in a reversible reactionA substance that decreases the rate of a reaction is calledIn autocatalysis, the catalyst isCollision theory was developed in 1916 to 1918 byA collision leads to products only if molecules have enough energy andThe steric factor P in collision theory accounts forCollision theory treats reactant molecules asThe number of collisions per second per unit volume of a reaction mixture is calledWho studied the inversion of sucrose in 1850, pioneering chemical kinetics?Who received the first Nobel Prize in Chemistry in 1901 for laws of chemical dynamics?In 1864 Waage and Guldberg published which law?Crushing a solid reactant speeds a reaction because itThe study of reactions initiated by light is calledWhich technique studies fast reactions by a sudden temperature or pressure change?Chemical equilibrium is reached when