ECAT Pre Engineering Chemistry Chapter 11 MCQ Test With Answer

Which of the following reactions occur at moderate rate :

• Rusting of iron A
• Chemical weathering of stone work of buildings by acidic gases in atmosphere. B
• Hydrolysis of an ester C
• Fermentation of sugars D

Which of the following may affect the rate constant (k) fro a reaction :

• Change in concentration. A
• Change in pressure. B
• Change in pH. C
• Change in temperature. 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 effective activity of a metal catalyst is increased if it is in

• Solid form A
• Liquid state B
• Gaseous state C
• Finely divided form D

• Zero A
• 253 sec B
• 150 sec C
• 500 sec 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

The unit of rate constant K ismole^-1 dm³for a chemical reaction, the order of reaction is :

• Order of reaction can determined by an experiment A
• Order of reaction can determined from a balance equation only. B
• Order of reaction can determined increases by increasing temperate. C
• Order of reaction must be in whole number and not in fraction. D

The unit of rate of reaction is

• mole dm^-3 A
• mole Kg^-1 B
• moles dm^-3sec^-1 C
• grams dm^-3 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

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
• 
  B
• 
  C
• 
  D

The chemical method used for determination of rate of reaction is

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

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

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

Which one of the following reaction rate is effected by the light

• 
  A
• 
  B
• 
  C
• 
  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

The rate of reaction is denoted by

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

It is common observation that rates of chemical reactions differ :

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

______ 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

The rate of reaction between two specific time intervals is called

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

The rate determining step is the :

• Slowest step. A
• Fastest step. B
• Moderate step. C
• Both (a) and (b). 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 example of a photo chemical reaction is photosynthesis has order of reaction :

• 1 A
• 2 B
• 0 C
• 3 D

• 1st order A
• 2nd order B
• Zero order C
• 3rd order 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 rate equation for a reaction is Rate =k[A]. what are unit of K ?

• Mole-1 dm³ S^-1

  A

• Mole dm³ S^-1

  B

• Mole dm³

  C

• S^-1

  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