Questions and answers for exam Preparation

MCQs

Total Questions : 2307 | Page 20 of 231 pages

Question 191. What is the unit of the rate constant in a chemical reaction in which 10% of the reactant decomposes in one hour, 20% in two hours, 30% in three hours and so on?

Litre/mole.second
Moles/litre.second
Litre/mole
Litre/second

Discuss Question

Answer: Option A. -> Litre/mole.second

Question 192. A back mix reactor is

Suitable for gas phase reactions
Ideal at very low conversion
Same as plug flow reactor (PFR)
Same as ideal stirred tank reactor

Discuss Question

Answer: Option D. -> Same as ideal stirred tank reactor

Question 193. A batch reactor is

Suitable for gas-phase reactions on commercial scale
Suitable for liquid phase reactions involving small production rate
Least expensive to operate for a given rate
Most suitable for very large production rate

Discuss Question

Answer: Option B. -> Suitable for liquid phase reactions involving small production rate

Question 194. A Catalyst

Increases the equilibrium concentration of the product
Changes the equilibrium constant of the reaction
Shortens the time to reach the equilibrium
None of these

Discuss Question

Answer: Option C. -> Shortens the time to reach the equilibrium

Question 195. A catalyst promoter

Improves the activity of a catalyst
Acts as a catalyst support
Itself has very high activity
All of the above

Discuss Question

Answer: Option A. -> Improves the activity of a catalyst

Question 196. The equilibrium constant K of a chemical reaction depends on

Temperature only
Pressure only
Temperature and pressure
Ratio of reactants

Discuss Question

Answer: Option A. -> Temperature only

Question 197. A photochemical reaction is

Accompanied with emission of light
Catalysed by light
Initiated by light
All of the above

Discuss Question

Answer: Option C. -> Initiated by light

Question 198. Pick out the wrong statement pertaining to space velocity of flow reactors.

The unit of space velocity is (time)⁻¹
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
The space velocity of 3 hr⁻¹ means that one third reactor volume of feed at specified conditions are being fed into the reactor
None of these

Discuss Question

Answer: Option 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

Question 199. A rise in temperature

Normally tends to increase the reaction rate
Does not affect a catalysed reaction
Does not affect photo-chemical reaction rates
All of the above

Discuss Question

Answer: Option D. -> All of the above

Question 200. A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the process is limited by