Chemical 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. Use of different catalysts in a reversible catalytic chemical reaction does not change the
equilibrium composition
B. Alumina is added as a promoter to iron catalyst in ammonia synthesis reaction
C. Activation energy for a reaction is obtained from the intercept of the Arrhenius plot
D. Presence of inerts affects the equilibrium conversion of

A. A particular chemical reaction is more temperature sensitive at low temperatures
B. A very high value of equilibrium constant, K (K >> 1) indicates that the reaction is practically
irreversible in nature
C. The intercept of the Arrhenius plot is called the ‘activation energy’
D. Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant
regions

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

A. In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time
B. In a semi-batch reactor, one reactant is charged batch wise, while the other reactant is fed continuously
C. In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system
D. In a continuous flow reactor, both the reactants and the products flow out continuously

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