Description : Half-life period for a first order reaction is __________ the initial concentration of the reactant. (A) Directly proportional to (B) Inversely proportional to (C) Independent of (D) None of these
Last Answer : (C) Independent of
Description : For a __________ order chemical reaction as shown in the bellow figure, the half life period is independent of the initial concentration of the reactant A. (A) Zero (B) First (C) Second (D) Third
Last Answer : (B) First
Description : If the time required to change the concentration of reactant to half its original value is independent of the initial concentration, the order of reaction is: (A) Zero (B) One (C) Two (D) Three
Last Answer : (B) One
Description : . In a zero order reaction, reactants concentration does not change with time and the (A) Time for half change is half the time taken for completion of the reaction (B) Time for ... is independent of the initial concentration (D) Reaction rate is trebled when the initial concentration is trebled
Last Answer : (A) Time for half change is half the time taken for completion of the reaction
Description : The knowledge of initial concentration and rate constant is necessary to determine the half life time of a reaction of __________ order. A) Zero (B) First (C) Second (D) None of these
Last Answer : (C) Second
Description : For a zero order chemical reaction, the (A) Half life period is directly proportion to the initial concentration of the reactants (B) Plot of products concentration with time is a straight line through the origin (C) Products concentration increases linearly with time (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : What is the order of a chemical reaction in which doubling the initial concentration of the reactants doubles the half life time of the reaction? (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (A) 0
Description : If the time required for half change is inversely proportional to the square of initial concentration and the velocity depends on the units in which the concentration term is expressed, then the order of reaction is (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (D) 3
Description : Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence ... D) Half life of a reaction increases with increased initial concentration for reaction orders more than one
Last Answer : (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same
Description : Half life period of a chemical reaction is (A) The time required to reduce the concentration of the reacting substance to half its initial value (B) Half of the space time of a reaction (C) Half of the residence time of a reaction (D) None of these
Last Answer : (A) The time required to reduce the concentration of the reacting substance to half its initial value
Description : The order of reaction is the number of moles whose concentrations determine the rate of a reaction at a given temperature Give the integrated equation for first order reaction. K = (2.303 / t) * log (a ... a' is the initial concentration of reactants x' is the amount reacted in time t seconds
Last Answer : What is Threshold energy ?
Description : Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants; but it is afunction of reaction temperature. In a chemical reaction, the time required to ... Then the order of this reaction is: (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (B) 1
Description : With increase in initial concentration, the fractional conversion of a first order reaction in a given time (A) Increases (B) Decreases (C) Remain constant (D) Unpredictable
Last Answer : (C) Remain constant
Description : Second order consecutive irreversible reaction as shown in the bellow figure, were carried out in a constant volume isothermal batch reactor with different initial feed compositions. Reactor temperature was same in all the cases. In experiments ... constants (k1 /k2 )? (A) 1/4 (B) 1/2 (C) 2 (D) 4
Last Answer : (A) 1/4
Description : Concentration of the limiting reactant (with initial concentration of a moles/litre) after time t is (a-x). Then 't' for a first order reaction is given by (A) k. t = ln a/(a - x) (B) k. t = x/a (a - x) (C) k. t = ln (a - x)/a (D) k. t = ln a (a - x)/x
Last Answer : (A) k. t = ln a/(a - x)
Description : For a zero order reaction, the concentration of product increases with the (A) Increase of reaction time (B) Increase in initial concentration (C) Total pressure (D) Decrease in total pressure
Last Answer : (A) Increase of reaction time
Description : When [s] is equal to Km, which of the following conditions exist? (A) Half the enzyme molecules are bound to substrate (B) The velocity of the reaction is equal to Vmax (C) The velocity of the reaction is independent of substrate concentration (D) Enzyme is completely saturated with substrate
Last Answer : Answer : A
Description : Rate of a chemical reaction is independent of the concentration of the reactants for a __________ reaction. (A) Zero order (B) Third order (C) Consecutive (D) None of these
Last Answer : (A) Zero order
Description : Pick out the wrong statement. (A) α-particle emission from a radioactive element makes it electrically negative (B) β-particle emission from a radioactive element makes it electrically ... ) The disintegration constant of a radioactive isotope is independent of pressure, temperature or concentration
Last Answer : (C) A radioactive element having a half life period of 20 years will completely disintegrated in 40 years
Description : With the same reaction time, initial concentration and feed rate, the reaction 2A → B is carried out separately in CSTR and P.F. reactor of equal volumes. The conversion will be (A) Higher in P.F. reactor (B) Higher in CSTR (C) Same in both the reactors (D) Data insufficient; can't be predicted
Last Answer : (A) Higher in P.F. reactor
Description : The rate constant of a reaction is a function of the (A) Time of reaction (B) Temperature of the system (C) Extent of reaction (D) Initial concentration of the reactants
Last Answer : (B) Temperature of the system
Description : The rate constant of a reaction depends on the (A) Initial concentration of reactants (B) Time of reaction (C) Temperature of the system (D) Extent of reaction
Last Answer : All of the carbon atoms are sp hybridized
Last Answer : (C) Temperature of the system
Description : “The enthalpy change for any chemical reaction is independent of the intermediate stages, provided the initial and final conditions are the same for each route.” This statement is known as: A. Dulong’s Law B. Dalton’s Law C. Hess’s Law D. Petit Law
Last Answer : Hess’s Law
Description : The Michaelis constant, Km is (A) Numerically equal to ½ Vmax (B) Dependent on the enzyme concentration (C) Independent of pH (D) Numerically equal to the substrate concentration that gives half maximal velocity
Last Answer : Answer : D
Description : In the gaseous phase ammonia formation reaction (N2 + 3H2 ⇌ 2NH3 ), the value of the equilibrium constant depends on the (A) Total pressure of the system (B) Volume of the reactor (C) Temperature (D) Initial concentration of N2 and H2
Last Answer : (C) Temperature
Description : In a consecutive reaction system of the given figure bellow, when E1 is much greater than E2 , the yield of B increases with the (A) Increase of temperature (B) Decrease of temperature (C) Increase in initial concentration of A (D) Decrease in initial concentration of A
Last Answer : (A) Increase of temperature
Description : If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower (C) Entropy changes (D) Free energy of activation is higher
Last Answer : (D) Free energy of activation is higher
Description : Equilibrium constant of a reaction varies with the (A) Initial concentration of the reactant (B) Pressure (C) Temperature (D) None of these
Last Answer : C) Temperature
Description : The rate of an enzyme catalyzed reaction was measured using several substrate concentrations that were much lower than Km, the dependence of reaction velocity on substrate concentration can best be ... constant fraction of Vmax (C) Equal to Km (D) Proportional to the substrate concentration
Last Answer : Answer : C
Description : The Michaehis-Menten hypothesis: (A) Postulates the formation of an enzyme substrate complex (B) Enables us to calculate the isoelectric point of an enzyme (C) States that the ... independent of substrate concentration (D) States that the reaction rate is proportional to substrate concentration
Description : Enzymes are destroyed, when the (A) Temperature is very high (B) Reactant's concentration is very high (C) Reactant's concentration is very low (D) Reaction rate is independent of the reactant's concentration
Last Answer : (A) Temperature is very high
Description : The reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m3 is fed to the reactor at the rate of 0.01 m3 /s and at a temperature of 500 K. If the exit ... /kmole. K (may be assumed to be independent of temperature)) (A) 400 (B) 500 (C) 600 (D) 1000
Last Answer : (C) 600
Description : Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of ... to (B) Independent of (C) Inversely proportional to (D) Proportional to the square o
Last Answer : (A) Proportional to
Description : At very high concentration of enzymes, the rate of fermentation chemical reaction is __________ the concentration of reactants. (A) Independent of (B) Directly proportional to (C) Inversely proportional to (D) Proportional to the square of
Last Answer : (A) Independent of
Description : Pick out the wrong statement. (A) Wine, rum & Vodka are prepared by the formulation of fruit juice, sugar beet & rye respectively (B) Protein catalysts are called enzymes (C) The rate ... concentration of reactants at high concentration of enzymes (D) Total sugar content in molasses is about 10%
Last Answer : (D) Total sugar content in molasses is about 10%
Description : When the velocity of an enzymatic reaction equals Vmax, substrate concentration is (A) Half of Km (B) Equal to Km (C) Twice the Km (D) Far above the Km
Description : Initial amount of the radioactive element with half life 10 days is 16 g. What amount in gm of this element will remain after 40 days?
Last Answer : Initial amount of the radioactive element with half life 10 days is 16 g. What amount in gm of this element will remain after 40 days?
Description : A radioactive element gets spilled over the floor of a room. Its half life period is 30 days. If its initial activity is ten times the permissible val
Last Answer : A radioactive element gets spilled over the floor of a room. Its half life period is 30 days. If its initial ... B. 1000 days C. 300 days D. 10 days
Description : The half life of radioactive isotope is 3 hour. If the initial mass of isotope were 256 g, the mass of it remaining undecayed after 18 hr is a)12 g b)
Last Answer : The half life of radioactive isotope is 3 hour. If the initial mass of isotope were 256 g, the mass of it remaining ... 4 g B. 8 g C. 12 g D. 16 g
Description : The radioisotope , tritium `(""_(1)^(3)H)` has a half-life of 12.3 years. If the initial amount of tritium is 32 mg , how many milligrams of it would
Last Answer : The radioisotope , tritium `(""_(1)^(3)H)` has a half-life of 12.3 years. If the initial amount of tritium is 32 ... A. 1 mg B. 2 mg C. 4 mg D. 8 mg
Description : At equilibrium the concentration of water in vapour phase (C* ) in kg/m3 of air space and the amount of water (m) adsorbed per kg of dry silica gel are related by, C* = 0.0667m. To maintain dry conditions in a room ... which the temperature is maintained constant) is (A) 0.0 (B) 0.2 (C) 0.4 (D) 1.0
Last Answer : (C) 0.4
Description : Plastic collosion of two bodies of equal mass results in a common velocity after impact which is a.Sum of their initial velocities b.Difference of their initial velocities c.Average of their initial velocities d.Independent of their initial velocities e.None of the above
Last Answer : e. None of the above
Description : Which of the following was not one of the initial demands of the Sri Lankan Tamils?(a) Recognition of Tamil as an official language (b) Regional autonomy (c) Equality of opportunity in securing jobs and education (d) Creation of an independent Tamil Eelam (state)
Last Answer : (d) Creation of an independent Tamil Eelam (state)
Description : Consider the following conditions : (a) The solution must be feasible, i.e. it must satisfy all the supply and demand constraints. (b) The number of positive allocations must be equal to m+n-1, where m is the number of rows and n is ... B) (a) and (c) only (C) (b) and (c) only (D) (a), (b) and (c)
Last Answer : (D) (a), (b) and (c)
Description : A liquid decomposes by irreversible first order kinetics and the half life period of this reaction is 8 minutes. The time required for 75% conversion of the liquid will be __________ minutes. (A) 4 (B) 8 (C) 12 (D) 16
Last Answer : (D) 16
Description : Half life period of decomposition of a liquid 'A' by irreversible first order reaction is 12 minutes. The time required for 75% conversion of 'A' is __________ minutes. (A) 18 (B) 24 (C) 6 (D) 12
Last Answer : (B) 24
Description : The conversion of a reactant, undergoing a first order reaction, at a time equal to three times the half life of the reaction is: (A) 0.875 (B) 0.5 (C) 0.425 (D) Data insufficient to calculate
Last Answer : (A) 0.875
Description : The following statement(s) is/are true concerning initial microbiologic diagnostic techniques. a. Appropriate expeditious transport of specimens to the microbiology laboratory is essential for obtaining accurate ... a 4-to 8-fold increase over the MIC to be considered clinically efficacious.
Last Answer : Answer: a, c, d Because most surgical infections are polymicrobial, specimens should be cultured for aerobic and anaerobic bacteria, as well as fungi. Although aerobic and aerotolerant ... fold increase over MIC during the peak serum level have been demonstrated to be clinically efficacious
Description : Mercury cells for caustic soda manufacture, compared to diaphragm cells (A) Require lower initial investment (B) Require more power (C) Produce lower concentration NaOH (D) None of these
Last Answer : (D) None of these