ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

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

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

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

• Measuring pH A
• Measuring density B
• Titration against standard NaOH C
• Titration against standard KMnO₄solution 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

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

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

In the hydrolysis of CH₃COOC₂H₅the acid produced is

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

It is common observation that rates of chemical reactions differ :

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

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

• Zero A
• 1 B
• 2 C
• 1.5 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

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

• Diastase A
• Lipase B
• Inverters C
• Zymase D

The experimental relationship between a reaction rate and the concentration of reactants is known as

• Order A
• Molecularity B
• Rate constant 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

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

In the hydrolysis of CH₃COOC₂H₅the acid produced is

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

The catalytic activity of Pt is much higher when

• It is mixed with asbestos A
• It is mixed with Pd B
• It is mixed with arsenic C
• In is made colloidal platinum D

• Rate = k[FeCl₃] [Kl]² A
• Rate = k[Fe⁺³][Cl^-1] [Kl] B
• Rate = k[Fe⁺³] [Cl^-1][K;] C
• Rate = k[Kl]³[FeCl₃]° D

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

Which statement is not correct

• Enzymes catalyst a specific reaction A
• Enzymes show catalytic activity at a specific temperature B
• The catalytic activity of enzymes is stopped if optimum pH is changed C
• The catalytic activity is poisoned by a co-enzymes 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

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

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

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

The example of a photo chemical reaction is photosynthesis has order of reaction :

• 1 A
• 2 B
• 0 C
• 3 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