- (A) In a first order reaction, A → products; the reaction becomes slower as it proceeds, because the concentration of A decreases and the rate is proportional to the concentration of A
- (B) Transition state theory approaches the problem of calculating reaction rates by concentrating on the idea of activated complexes
- (C) According to the penetration theory, the mass transfer co-efficient decreases, if the exposure time of an eddy to the solute decreases
- (D) If the rate of an irreversible reaction, A + B → 2C is k.C
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- (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
- (A) The unit of space velocity is (time)-1
- (B) The space velocity of 3 hr-1 means that three reactor volumes of feed at specified conditions are being fed into the reactor every hour
- (C) The space velocity of 3 hr-1 means that one third reactor volume of feed at specified conditions are being fed into the reactor
- (D) None of these
- (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
- (A) Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C
- (B) Most of the enzyme catalysed reactions involve at least two substrates
- (C) Enzymes help in increasing the activation energy of the reaction
- (D) Equilibrium concentrations in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & products
- (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
- (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
- (A) Recycled coarse material to the grinder by a classifier is termed as circulating load
- (B) Wear and tear in wet crushing is more than that in dry crushing of materials
- (C) Size enlargement (opposite of size reduction) is not a mechanical operation
- (D) A ‘dust catcher’ is simply an enlargement in a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas
- (A) Close circuit grinding is more economical than open circuit grinding
- (B) Cod oil, beef tallow or aluminium stearates are used as grinding aids in cement ‘industries’
- (C) The equipment used for the removal of traces of solids from a liquid is called a classifier
- (D) Size enlargement is a mechanical operation exemplified by medicinal tablet making
- (A) Removal of iron from ceramic material is necessitated (by magnetic separation method) so as to avoid discolouration of ceramic products
- (B) The operating cost of shaking screen is more than that of a vibrating screen
- (C) Screen capacity does not depend upon the specific gravity of the minerals
- (D) Asphalt is best crushed using toothed roll crusher
