ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

Which of the following reactions occur at moderate rate :

• Rusting of iron A
• Chemical weathering of stone work of buildings by acidic gases in atmosphere. B
• Hydrolysis of an ester C
• Fermentation of sugars D

The unit of the rate constant is the same as that of rate of reaction in :

• Third order reaction A
• Second order reaction B
• First order reaction C
• Zero order reaction D

• Initial concentration of reaction A
• Initial concentration of products B
• Final concentration of products C
• Order of the reaction D

• 2 A
• 3 B
• 4 C
• 9 D

The experimental relationship between a reaction rate and the concentration of reactants is known as

• Order A
• Molecularity B
• Rate constant C
• Rate law D

The number of atoms or molecules whose concentrations determine the rate of the reaction is called

• Molecularity A
• Order B
• Rate of reaction C
• Rate constant D

Which of the following may affect the rate constant (k) fro a reaction :

• Change in concentration. A
• Change in pressure. B
• Change in pH. C
• Change in temperature. D

In zero order reaction, the rate is independent of :

• Temperature of reaction A
• Concentration ofreactants B
• Concentration of products C
• None of these. D

When the rate of reaction is entirely independent of the conc. of reaction molecules then order of reaction is

• Zero A
• First B
• Second C
• Third D

The rate of reaction :

• Increase as the reaction proceeds. A
• Decreases as the reaction proceeds. B
• Remains the same as the reaction proceed. C
• May decrease or increase as the reaction proceeds. D

In the manufacture of NH₃by Haber's process catalyst used is iron its catalytic efficiency is poisoned by

• Presence of Al₂O₃ A
• Presence of Cr₂O₃ B
• MnO₂ C
• CO present with H₂gas D

The unit of rate constant is the same as that of the rate of reaction in :

• First order reaction. A
• Second order reaction. B
• Zero order reaction. C
• Third order reaction. D

The rate of reaction is denoted by

• dc/dp A
• dc/ac B
• dc/dT C
• dc/dt D

Activation energy is the difference of energy between the energy of the reactant and

• The product A
• The activated complex B
• Both a and b C
• None of these D

• First order A
• Pseudo first order B
• Second order C
• Zero order D

• Zero A
• 1 B
• 2 C
• 1.5 D

The addition of a catalyst to a reaction changes the

• Enthalpy A
• Entropy B
• Nature of reactants C
• Energy of activation D

With increases of 10°C temperature the rate of reactiondoubles. This increase in rate of reactionis due to :

• Decrease in activation energy or reaction. A
• Decrease in number of collisions between reactant molecules. B
• Increase in activation energy of reactants. C
• Increase in number of effective collisions D

• Diastase A
• Lipase B
• Inverters C
• Zymase D

The rate determining step is the :

• Slowest step. A
• Fastest step. B
• Moderate step. C
• Both (a) and (b). D

Which statement is true about order of reaction :

• Order of reaction can only be determined by an experiment. A
• Order of reaction can be determined from a balance equation only. B
• Order of reaction increase by increasing temperature. C
• Order of reaction must be in whole number and not in fraction. D

The rate constant k of a reaction activation energy Ea and temperature are related by Arrhenius in the form of an equation which is

• 
  A
• 
  B
• 
  C
• 
  D

• Zero A
• 253 sec B
• 150 sec C
• 500 sec D

• Small change in concentration of product A
• Small time internal B
• Co-efficient of the reactant C
• Co-efficient of the product D

Dilatometer method is useful for the reaction that involve :

• Small volume changes in solutions A
• Change in infractive indices B
• Where reactants absorb U.V, visible or infrared radiation C

A zero order reaction is one in which :

• Rate is not affected by changing concentration of reactants. A
• concentration of reactants do not change with the passage of time. B
• Reactants do not react. C
• One reactants in large excess. D

Which of the following will affect the rate :

• First step of reaction. A
• Last step of reaction. B
• Rate determining step. C
• Fastest step. D

• Homogeneous A
• Heterogeneous B
• Isogeneous C
• None D

The experimental relationship between a reaction rate and the concentration of reactants is called

• Order or reaction A
• Rate law B
• Activated complex C
• Molecularity D

• Rate is independent of concentration of water since it is in excess A
• Rate is independent of concentration of ester since it is in exces B
• Rate depends upon the concentration of acid catalyst added C
• Rate = k[CH₃COOC₂H₅]^1/2[H₂O]^1/2 D