ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

If initial concentration of the reactants and half life period of the reaction is known, then we can determine

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

The rate determining step is the :

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

• Zero A
• 1 B
• 2 C
• 1.5 D

______ are called biocatalysts

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

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

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 rate of reaction determined at a given time is called

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

which one of the following is a heteroheneous catalysis

• 
  A
• 
  B
• 
  C
• 
  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

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 factor which effect the rate of reaction

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

Hydrogenation of vegetable oils is accelerated by Ni catalyst. The catalytic activity of Bi is increased by a promoter of activator which is

• Na and K A
• Na and Hg B
• Hg and Zn C
• Cu and Te 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 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

If a reactant or product of a reaction absorbs radiation, then physical method for determining the rate of reaction is

• Spectrometry A
• Refractometry B
• Conductivity measurement C
• Optical method D

In the hydrolysis of CH₃COOC₂H₅the acid produced is

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

Decreases om concentration of reactant is denoted by

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

If the rate of reaction is independent of the concentration of the reactant, the reaction is of

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

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

Factor which slows down the rate of reaction is

• Small size of the particles of the reactant A
• High temperature of reaction B
• More concentration of reactant C
• Lowering the temperature 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

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

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

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

• Measuring pH A
• Measuring density B
• Titration against standard NaOH C
• Titration against standard KMnO₄solution 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 actual number of atoms or molecules taking part in rate determining step is

• Rate of reaction A
• Velocity of reaction B
• Order of reaction C
• Molecularly D