A. A chemical reaction accompanied by absorption of heat is called an exothermic reaction
B. A chemical reaction accompanied by evolution of heat is called an endothermic reaction
C. The rate constant for a first order reaction does not change on changing the concentration units
D. Chemical equilibrium state is dynamic in nature
Related Mcqs:
- Pick out the correct statement ?
A. A catalyst speeds up the forward reaction but slows shown the reverse reaction
B. Addition of catalyst changes the equilibrium constant
C. Pressure changes do not change the equilibrium concentrations
D. The composition of equilibrium is changed by catalyst - Pick out the correct statement ?
A. A catalyst does not change AH of the reaction
B. A catalyst changes the equilibrium point
C. Law of mass action was suggested by Le-Chatelier
D. The difference between the energy of reactants and that of the products is the activation
energy - Pick out the correct statement?
A. In catalytic reactions, the catalyst reacts with the reactants
B. A catalyst initiates a chemical reaction
C. A catalyst lowers the activation energy of the reacting molecules
D. A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction - Pick out the correct statement?
A. A lower temperature favours the reaction of lower activation energy
B. The dispersion number for a reactor/vessel is uL/D
C. The rate controlling step in a reaction involving many steps is the fastest step
D. Pore volume and porosity of a catalyst is measured by Brunauer-Emmett-Teller (BET)
technique - Pick out the correct statement?
A. Reactions with high activation energies are very temperature sensitive
B. Chemical equilibrium is a static state
C. A photochemical reaction is catalysed by light
D. A chemical reaction occurs when the energy of the reacting molecule is less than the activation energy of the reaction - If n = overall order of a chemical reaction. a = initial concentration of reactant. t = time required to complete a definite fraction of the reaction. Then pick out the correct relationship ?
A. t ∝ 1/an
B. t ∝ 1/an – 1
C. t ∝ 1/an + 1
D. t ∝ an - 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 - Pick out the wrong statement ?
A. The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and
infinity respectively
B. Space time in a flow reactor is a measure of its capacity and is equal to the residence time when the density of reaction mixture is constant
C. Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a
particular duty
D. In an ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction - Pick out the wrong statement?
A. Exit age description function E. and internal age distribution function (I) are related as, E = -(dI/dθ)
B. Chemisorption studies are useful in the determination of catalyst surface area and pore size distribution
C. A higher temperature favours the reaction of higher activation energy
D. A catalyst increases the potential energy barrier over which the reactants must pass to form products - Pick out the wrong statement?
A. The integral method of analysing kinetic data is used when the data is scattered
B. The differential method of analysing kinetic data requires more accurate or larger amounts of data
C. When the reaction rate is independent of temperature, the reaction is said to be of zero order
D. The ratio of volumes of plug flow reactor to that of mixed reactor is always less than one for identical feed composition, flow rate, conversion and for all positive reaction orders