ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

which one of the following is a heteroheneous catalysis

• 
  A
• 
  B
• 
  C
• 
  D

The rate equation for a reaction is Rate =k[A]. what are unit of K ?

• Mole-1 dm³ S^-1

  A

• Mole dm³ S^-1

  B

• Mole dm³

  C

• S^-1

  D

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

If half life period of a reaction is independent of the concentration of the reactants, then the reaction is

• Zero order A
• First order B
• Second order C
• Order is in fraction D

All reactions occur in :

• A single step. A
• A series of steps B
• Two steps. C
• Both (a) and (b) D

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

In the expression rate = K [A]^a[B]^bK is

• The order of reaction A
• The speed of reaction B
• The specific rate constant C
• The overall order of reaction D

In an experiment the concentration of a reactant 'A' is doubled the rate increases four times. If concentration in tripled, then rate increases nint times. Thus the rate is proportional to ______ of concentration of 'A'

• Square root A
• Square B
• Twice C
• Cube D

Which of the following factors does not influenced the rate of reaction

• Concentration of the reaction A
• Nature of the reactants B
• Molecularity of the reaction C
• Temperature 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

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 thermal decomposition of N₂O the half life period for two different initial concentrations of N₂O are

(i) 255 second for initial N₂O 290 mm Hg

(ii) 212 second for initial N₂O 360 mm Hg then it is

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

The value of activation energy Ea of a reaction can be determined from the value of slope of the straight line obtained by plotting a graph between 1/T and log k. the value of Ea is equal to

• Slope A
• 1/Slope B
• Slope x R C
• Slope x 2.303 R D

• 2 A
• 3 B
• 4 C
• 9 D

Complex protein molecules which catalyses the organic reactions in the living cells are called

• Living organisms A
• Enzymes B
• Viruses C
• Bacteria D

A substance which increases the rate of a reaction without being consumed during the reaction is called

• An autocatalyst A
• A catalyst B
• A negative catalyst C
• All of these D

Group l-A elements react with water fastly than the reaction of group ll-A elements because

• l_Aelements are more soft then ll_A A
• l_Aelements are non-metals B
• l_Aelements have 1 electron in their outermost s-orbital and are strongly electropositive C
• l_Aelements make ionic bond 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

Which statement about Arrhenius equation is incorrect

• Factor 'A' called Arrhenius constant depends upon collision frequency of reactants A
• Rate of reaction increase by increasing temperature B
• Rate constant k is increased C
• Activation energy Ea is decreased by rise in temperature 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

The factor which effect the rate of reaction

• Nature of reactants A
• Surface area B
• Light C
• All of the above 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

It rate law of an equation is written asdx/dt=K[A][B] ?

• Reaction is independent of the concentration of A and B. A
• Product is decreasing with passage of time. B
• Reactant in increasing with passage of time. C
• Reactant is increasing with passage of time. 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

The rate of reaction between two specific time intervals is called

• Instantaneous rate A
• Average rate B
• Specific rate C
• Ordinary rate D

Optical rotation method is sued when

• Reaction involve ions A
• Change of refractive indices B
• Reactions involving change of optical activity C
• None of the above D

The chemical method used for determination of rate of reaction is

• Spectroscopic A
• Conductiometric B
• Refractometric C
• Titration 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

For a chemical reaction to take place the particles must have sufficient energy for the effective collisions, the energy is called

• Average energy A
• Activation energy B
• Potential energy C
• Collision energy D

If the rate of decay of radioactive isotope decreases from 200 cpm to 25 cpm after 24 hours, what is its half life :

• 8 hours A
• 6 hours B
• 4 hours C
• 3 hours D