ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

In the reaction of oxalic acid with KMnO₄and H₂SO₄is slow at the beginning but after sometimes the reaction becomes faster due to

• Formation of MnSO₄which acts as 'Auto catalyst A
• Formation of CO₂which acts as 'Auto catalyst B
• Formation of K₂SO₄which acts as 'Auto catalyst C
• Evolution of O₂gas which acts as 'Auto catalyst 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

which one of the following is a heteroheneous catalysis

• 
  A
• 
  B
• 
  C
• 
  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 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

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

______ are called biocatalysts

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

Decreases om concentration of reactant is denoted by

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

A white precipitate ofsilver chlorideimmediately formed on additionof :

• Silver nitrate solution to sodium chloride solution. A
• Silver chloride solution to sodium nitrate solution. B
• Silver nitrate solution to potassium chloride solution C
• Silver nitrate solution to hydrogen chloride solution. 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

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

For effective collisions the molecules slow down before collision and their kinetic energy decreases which results in increase in their

• Activation energy A
• Average energy B
• Potential energy C
• Collisions frequency 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

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 we perform the same reaction by taking two different initial concentrations of a reactant for a second order reaction then

• Reaction becomes exothermic A
• Energy of activation is different B
• Mechanism of reaction is changed C
• Half life period is changed 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

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

The factor which effect the rate of reaction

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

• 2 A
• 3 B
• 4 C
• 9 D

Platinum is poisoned by

• Arsenic A
• Silver B
• Argon C
• Zinc D

The chemical method used for determination of rate of reaction is

• Spectroscopic A
• Conductiometric B
• Refractometric C
• Titration D

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

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

Which of the following is not affected by light

• 
  A
• 
  B
• 
  C
• 
  D

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

When initial concentration of reactants an order of reaction is given, then its half life period can be calculated by the equation

• 
  A
• 
  B
• 
  C
• 
  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

In the hydrolysis of CH₃COOC₂H₅the acid produced is

• Inhibitor A
• Catalyst B
• Auto catalyst C
• None of above D