In a first order reaction, the time required to reduce the concentration of reactant from 1 mole/litre to 0.5 mole/litre will be __________ that required to reduce it from 10 moles/litre to 5 moles/litre in the same volume.

Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants ; but it is a function of reaction temperature. In a chemical reaction, the time required to reduce the concentration of reactant from 100 gm moles/litre to 50 gm moles/litre is same as that required to reduce it from 2 gm moles/litre to 1 gm mole/litre in the same volume. Then the order of this reaction is

A

0

B

1

C

2

D

3

For the reaction, A = X + Y, the respective concentrations are C_A, C_X and C_Y. The forward reaction rate constant is kf and the backward reaction rate constant is kb. Choose the correct statement from the following:
P. At equilibrium, kf C_A > k_B CxCy
Q. If the reaction is irreversible than, kb C_XC_Y = 0
R. The backward reaction rate will essentially be first order, if the forward reaction rate is first order.
S. Activation energy for the first order forward reaction will be independent of temperature.

A

P, Q

B

Q, R

C

R, S

D

Q, S

The configurations of the reactant and the product in the following reaction, are

A

R, R

B

R, S

C

S, R

D

S, S

Which concentration plot is linear for a first order reaction? (A is one of the reactant) versus time b) 2 versus time c) Ln versus time d) √ versus time

A

versus time

B

A

C

A

D

A

In the reaction,

if the concentration of both the reagents is doubled then the rate of the reaction will

A

remain unchanged

B

quadruple

C

reduce to one fourth

D

double

If the time required to change the concentration of reactant to half its original value is independent of the initial concentration, the order of reaction is

A

Zero

B

One

C

Two

D

Three

In a batch process, the reaction takes place in the presence of an acid medium. The acid is drained from the reaction vessel at the rate of 15ml/s as a result of the density difference of the acid from the reacting component. To avoid wastage of acid, it is recycled to an acid tank which has 1000 L capacity. The acid drained from the reaction vessel, picks up 50 g/L solids from the reactor. Acid is fed once again to the process from acid tank. When the process is started, the acid is almost pure in the tank as a result of filtration. As the reaction proceeds, acid in the tank gets more and more contaminated with the solids. The concentration of the solids should not exceed 100 g/L from the process point of view. The batch time is 16h. Estimate whether the concentration of the solids will exceed 100g/L during the batch reaction.

A

37.04 h

B

30.05 h

C

36.04 h

D

32.05 h

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

$${\text{t}} \propto \frac{1}{{{{\text{a}}^{\text{n}}}}}$$

B

$${\text{t}} \propto \frac{1}{{{{\text{a}}^{{\text{n}} - 1}}}}$$

C

$${\text{t}} \propto \frac{1}{{{{\text{a}}^{{\text{n}} + 1}}}}$$

D

$${\text{t}} \propto {{\text{a}}^{\text{n}}}$$

For a first order chemical reaction, the concentration of the reactant decreases __________ with time.

A

Linearly

B

Exponentially

C

Logarithmically

D

Inversely

The reaction between ethylene and hydrogen bromide to form ethyl bromide is carried out in a continuous reactor. C2H4 + HBr = C2H5Br The product stream is analyzed and found to contain 51.7 mole% C2H5Br and 17.3% HBr. The feed to the reactor contains only ethylene and hydrogen bromide. Calculate the fractional conversion of the limiting reactant and the percentage by which the other reactant is in excess. If the molar flow rate of the feed stream is 165 mol/s, what is the extent of reaction?

A

56.2 mol/s

B

45.6 mol/s

C

55.6 mol/s

D

44.6 mol/s