Enzymes are destroyed, when the_______________?

Related Mcqs:

1. Enzymes (a protein) are catalysts found in organisms. Its efficiency of catalysing a reaction is due to its capacity to lower the activation energy of the reaction. The enzyme ptyalin used for food digestion is present in ___________________?

   A. Blood
   B. Saliva
   C. Intestine
   D. Gland

2. The catalytic activity of enzymes is due to their capacity to lower the ______________ energy?

   A. Activation
   B. Potential
   C. Kinetic
   D. None of these

3. Sulphuric acid is used as a catalyst in the_______________?

   A. Hydrogenation of oils
   B. Gas phase oxidation of SO2 in chamber process
   C. Alkylation of hydrocarbons
   D. None of these

4. Batch process is preferred over continuous process, when the___________________?

   A. Product yields and quality cannot be achieved in continuous process, because of long
   residence time
   B. Sales demand of product is not steady
   C. Same equipment cannot be used for several processes of the same nature
   D. All A., B. & C.

5. Pick out the wrong statement ?

   A. For the same conversion, the holding time required in a batch reactor, is always equal to the space time required in a PFR
   B. Two mixed reactors of unequal size are available for producing a specified product, formed by
   a homogenous second order reaction. To achieve maximum production rate, the smaller
   reactor should be placed in series before the larger reactor
   C. Arrhenius equation describing the effect of temperature on rate constant is given by,
   K = A.e-Ea/RT
   D. The mechanism for the decomposition of CH3CHO into CH4 and CO in presence of I2 is:
   CH3CHO + I2 → CH3I + HI + CO; slow
   CH3I + HI → CH4 + I2; fast
   Then the rate of disappearance of CH3CHO is equal to K.CCH3I.CHI and acts as a catalyst

6. The reaction rate almost gets doubled for 10°C rise in temperature. This is due to the fact that the_________________?

   A. Increased temperature reduces the activation energy
   B. Fraction of molecules having threshold energy increases
   C. Collision frequency increases
   D. Value of threshold energy decreases

7. Given, 3H2 + CO = CH4 + H2O, KP = 101.84 and, 4H2 + CO2 = CH4 + 2H2O, KP = 101.17 the KP for the reaction CO + H2O = CO2 + H2 is __________________?

   A. 103.01
   B. 10-0.67
   C. 10-3.01
   D. 100.67

8. In a CSTR _______________ varies with time ?

   A. Reaction rate
   B. Concentration
   C. Both A. & B.
   D. Neither A. nor B.

9. Pick out the wrong statement ?

   A. ‘Hold back’ is defined as the fraction of material that stays longer than the mean residence time
   B. Study of non-ideal flow reactor is done experimentally by stimulus-response technique
   C. For studying a chemical reaction, it is desirable to monitor the reactants during initial stages
   and the products during the final stages of reaction
   D. A batch reactor cannot be used to study the kinetics of catalytic reaction

10. Which of the following is a characteristic of an ideal plug flow reactor ?

    A. Axial dispersion
    B. Flat velocity profile
    C. Uniform mixing
    D. None of these