Chemical Reaction Engineering(Chemical Engineering ) Questions and answers for exam Preparation

Question 1. For the chemical reaction P → Q, it is found that the rate of reaction doubles as the concentration of 'P' is doubled. If the reaction rate is proportional to Cpn, then what is the value of 'n' for this chemical reaction

1
2
3
0

Explanation:-

Answer: Option A. -> 1

Question 2. Reaction rate of a first order reaction, which is half completed in 23 minutes will be

0.03 sec-1
0.03 min-1
0.03 hr-1
0.05 min-1

Explanation:-

Answer: Option B. -> 0.03 min-1

Question 3. Reactant and product streams). The amount of heat to be removed is

$$\frac{2}{3}$$ kW
1 kW
$$\frac{5}{3}$$ kW
4 kW

Explanation:-

Answer: Option C. -> $$\frac{5}{3}$$ kW

Question 4. In an exothermic reaction, the energy of the reacting substances as compared to that of products is

More
Less
Same
Either A or B, depends on order of reaction

Explanation:-

Answer: Option A. -> More

Question 5. The effect of increasing pressure on the gaseous equilibrium of the reaction 2X+3Y ⇋ 3X+2Y indicates that

Pressure has no effect
Backward reaction is favoured
Forward reaction is favoured
None of these

Explanation:-

Answer: Option A. -> Pressure has no effect

Question 6. A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and $${{\text{k}}_{\text{g}}}$$ respectively. The effective rate constant (keff) is given by

$${{\text{k}}_{\text{e}}}{\text{ff}} = {\text{k}} + {{\text{k}}_{\text{g}}}$$
$${{\text{k}}_{\text{e}}}{\text{ff}} = \frac{{{\text{k}} + {{\text{k}}_{\text{g}}}}}{2}$$
$${{\text{k}}_{\text{e}}}{\text{ff}} = {\left( {{\text{k}}{{\text{k}}_{\text{g}}}} \right)^{\frac{1}{2}}}$$
$$\frac{1}{{{{\text{k}}_{\text{e}}}{\text{ff}}}} = \frac{1}{{\text{k}}} + \frac{1}{{{{\text{k}}_{\text{g}}}}}$$

Explanation:-

Answer: Option D. -> $$\frac{1}{{{{\text{k}}_{\text{e}}}{\text{ff}}}} = \frac{1}{{\text{k}}} + \frac{1}{{{{\text{k}}_{\text{g}}}}}$$

Question 7. Higher free energy of activation of a chemical reaction (at a given temperature) implies

Slower rate of reaction
Higher rate of reaction
Higher equilibrium conversion
Both B and C

Explanation:-

Answer: Option A. -> Slower rate of reaction

Question 8. Catalyst is a substance, which __________ chemical reaction.

Increases the speed of a
Decreases the speed of a
Can either increase or decrease the speed of a
Alters the value of equilibrium constant in a reversible

Explanation:-

Answer: Option A. -> Increases the speed of a

Question 9. The half life period of a first order reaction is given by (where, K = rate constant. )

1.5 K
2.5 K
$$\frac{{0.693}}{{\text{K}}}$$
6.93 K

Explanation:-

Answer: Option C. -> $$\frac{{0.693}}{{\text{K}}}$$

Question 10. A chemical reaction is of zero order, when the reaction rate is (where, CA = concentration of reactant)

$$ \propto {\text{CA}}$$
$$ \propto \frac{1}{{{\text{CA}}}}$$
Independent of temperature
None of these

Explanation:-

Answer: Option D. -> None of these