ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

• Three times A
• Six times B
• Nine times C
• Two times D

The rate of reaction :

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

Rate of chemical reaction depends upon :

• The number of total collisions per second. A
• Number of molecules taking part in a chemical reaction. B
• Number of fruitful collisions per second C
• Number of fruitless collisions per second. D

A pseudo uni-molecular reaction has order of reaction :

• 3 A
• 2 B
• 1 C
• 0 D

The rate of reaction is denoted by

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

A catalyst is a substance which increase the rate of a chemical reaction, but remains unchanged at the end of reaction, nut remains unchanged at the end of reaction, because

• It increases the temperature A
• It increase the surface area B
• It increases the rate constant C
• It decrease the energy energy of activation D

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

To determine the rate of reaction chemically a graphical method is applied. A graph is plotted between the amount or reactant decomposed or product formed against the time. The rate d_x/d_tat any time is equal to

• k A
• Tangentθ B
• 1/a, a is initial conc. C
• 1/a² 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

Value of rate constant k is specific for a reaction, and varies from reaction to reaction. The value of k of a reaction changes with

• Time A
• Temperature B
• Concentration of reactants C
• Order of reaction D

Homogenous catalysis is that in which catalyst and reactants are in same phase. Which one of the following reaction is a homogenous catalysis

• 
  A
• 
  B
• 
  C
• 
  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

The chemical method used for determination of rate of reaction is

• Spectroscopic A
• Conductiometric B
• Refractometric C
• Titration 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

The change in concentration of reactant or product per unit time is called :

• Rate constant. A
• Rate of reaction. B
• Rate equation. C
• Rate law. 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

Half life period of a reaction is inversely proportion to the initial concentration of the reactant, then order of reaction is

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

• 1st order A
• 2nd order B
• Zero order C
• 3rd order D

______ are called biocatalysts

• Organic acids A
• Organic bases B
• Enzymes C
• All D

The rate of reaction b/w two specific time intervals is called :

• Instantaneous rate of reaction. A
• Average rate of reaction. B
• Rate of a reaction. C
• Minimum rate of a reaction. 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

Half life period of a first order reaction is independent of:

• Presence of catalyst. A
• Conditions of temperature B
• Initial concentration of the compound C
• All of above D

Decreases om concentration of reactant is denoted by

• dc/dt A
• -dc/dt B
• +dc/dt C
• None 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

The sum of the exponents of the conc. terms in the rate equation is called

• Rate of reaction A
• Order of reaction B
• Specific rate constant C
• Average rate D

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

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

Which of the following is not affected by light

• 
  A
• 
  B
• 
  C
• 
  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

Refrectrometric method is used when

• Reactions involving absorption of I.R. or U. V A
• Reactions involving change of refractive index B
• Reactions involving ions C
• Change of optical activity D