ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

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

With the progressive of the reaction the slope of the curve between concentration of product and time

• Gradually becomes more steep A
• Gradually becomes less steep B
• No change occurs in slope C
• None of these occurs D

The unit rate of constan K ismole^-1 dm³S^-1for a chemical reaction, the order of reaction is :

• 3 A
• 2 B
• 1 C
• 0 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

In zero order reaction, the rate is independent of :

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

In the hydrolysis of CH₃COOC₂H₅the acid produced is

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

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

Half life period of N₂O₅is 24 minutes and it remains same where we increase or decrease its initial concentration, then reactions

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

It is common observation that rates of chemical reactions differ :

• Greatly. A
• A little bit. B
• Moderately. C

• 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

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

The rate determining step is the :

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

When copper is allowed to react with HNO₃, the reaction is slow in the beginning, finally becomes very fast. It is due to the formation of an auto catalyst which is

• Cu(NO₃)₂ A
• CuO B
• O₂ C
• HNO₂ D

The addition of a catalyst to a reaction changes the

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

In exothermic reaction decrease in potential energy of the products will result in

• Decreases in kinetic energy of the particles A
• Increases in kinetic energy of the particles B
• No change in kinetic energy C
• Decreases in activation energy 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

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

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

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

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

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

The reaction rate is expressed in the units of

• mol dm^-3S^- A
• mol dm^-3 B
• mol dm^-3N^- C
• dm^-3S^- 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 the hydrolysis of CH₃COOC₂H₅the acid produced is

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

Which technique is used to determine the absorption of radiations?

• Dilatometer method

  A

• Optical rotation method

  B

• Spectrometry

  C

• Refractometric method

  D