Chemical Kinetics Test

Result

Chemical Kinetics Test - 16

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

For which order reaction, the unit of rate constant is $$time^{-1}?$$

A
Zero order

B
First order

C
Second order

D
Third order

Solution

Units of rate constant for n order $$=mol^{1-n}L^{n-1}S^{-1}$$.
Given, unit of rate constant$$=mol^0L^0time^{-1}$$.
On comparing, $$0=n-1$$
$$\because n=+1$$
Question 2
1 / -0

What happen with the rate of the reaction when the frequency and the number of effective collisions between reacting particles increases?

A
Increases

B
Decreases

C
Remains the same

D
Approaches zero

E
None of the above

Solution

The atoms, ions and molecules can react to form products when they collide with enough kinetic energy and at favorable orientation. On increasing the frequency and the number of effective collisions between reacting particles increases the chance of reactants to come together to form a product that results in the increase of rate of the reaction.
Question 3
1 / -0

The reaction rate becomes double when the temperature increases :

A
approx $$50^{\circ}$$C.

B
approx $$10^{\circ}$$C.

C
approx $$15^{\circ}$$C.

D
approx $$20^{\circ}$$C.

Solution

With approximately $$10^0C$$ rise in temperature the reaction rate becomes double.

$$\dfrac{K_T}{K_{T+10}}=\dfrac{1}{2}$$
Question 4
1 / -0

Which of the following theory is not related to the chemical kinetics?

A
Collision theory

B
Absolute theory

C
Absolute reaction rate

D
VSEPR theory

Solution

Valence shell electron pair repulsion (VSEPR) theory is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms.
It's not related to the chemical kinetics.
Question 5
1 / -0

Chemical kinetics, a branch of physical chemistry, deals with:

A
heat changes in a reaction

B
physical changes in a reaction

C
rate of reactions

D
structure of molecules

Solution

Chemical word is related to reaction and kinetics is related to speed or rate, hence in chemical kinetics we study rate of reaction.
Question 6
1 / -0

For which of the following, the units of rate and rate constant of the reaction is identical?

A
First order reaction

B
Zero order reaction

C
Second order reaction

D
Fractional order reaction

Solution

Rate for a zero order reaction is given by
$$Rate=\left( rate\quad constant \right) \times \left( conc.\quad of\quad reactant \right) °$$
For example let
$$A+B\rightarrow C+D$$
be a zero order reaction then
$$\cfrac { -dA }{ dt } =\cfrac { -dB }{ dt } \Rightarrow K\left[ A \right] °\left[ B \right] °=K$$
hence units of rate and rate constant is identical.
Question 7
1 / -0

For determining the graph of an elementary bimolecular reaction process, all of the following must be determined except:

A
the energy of the reactants.

B
the activation energy of the reaction.

C
the energy of the intermediate.

D
the energy of the products.

Solution

Elementary reaction is a single step reaction in which no intermediate forms.
Reason-If intermediate forms in any step of the reaction then it must be produced in any another step.
Therefore, the correct option is (C)
Question 8
1 / -0

What causes an increase in effective collisions without increasing average energy?

A
An increase in the reactant concentration

B
An increase in the temperature

C
A decrease in pressure

D
Catalysts

Solution

As the concentration of the reactant increases, effective collision between the reactant molecules also increases. And thus, the reaction rate also increases. It is the main principle of the collision theory.
Option A is the correct answer.
Question 9
1 / -0

A zero order reaction is one:

A
in which reactants do not react

B
in which one of the reactants is in large excess

C
whose rate is uniform and not affected by time

D
whose rate increases with time

Solution

Rate for a zero order reaction is given by
$$Rate=\left( rate\quad constant \right) \times \left( conc.\quad of\quad reactant \right) °$$
For example let
$$A+B\rightarrow C+D$$
be a zero order reaction then
$$\cfrac { -dA }{ dt } =\cfrac { -dB }{ dt } \Rightarrow K\left[ A \right] °\left[ B \right] °=K$$
hence rate is independent of time for a zero order reaction.
Question 10
1 / -0

The order and molecularity of the chain reaction, $${ H }_{ 2 }\left( g \right) +{ Cl }_{ 2 }\left( g \right) \xrightarrow [ ]{ \quad hv\quad } 2HCl\left( g \right) $$, are:

A
$$2, 0$$

B
$$0, 2$$

C
$$1, 1$$

D
$$3, 0$$

Solution

The given reaction is a photochemical reaction. The order of this reaction is zero as the rate is independent of the concentrations of hydrogen and chlorine.

Molecularity is the no. of molecules that come together to react in the elementary step. In the given reaction, 2 molecules (1 molecule each of $$H_2$$ and $$Cl_2$$) react to form the product. Hence, the molecularity is 2.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Chemical Kinetics Test - 16

Result

Chemical Kinetics Test - 16

Score

-

Rank

-

SHARING IS CARING

Question 1

Zero order

First order

Second order

Third order

Solution

Question 2

Increases

Decreases

Remains the same

Approaches zero

None of the above

Solution

Question 3

approx $$50^{\circ}$$C.

approx $$10^{\circ}$$C.

approx $$15^{\circ}$$C.

approx $$20^{\circ}$$C.

Solution

Question 4

Collision theory

Absolute theory

Absolute reaction rate

VSEPR theory

Solution

Question 5

heat changes in a reaction

physical changes in a reaction

rate of reactions

structure of molecules

Solution

Question 6

First order reaction

Zero order reaction

Second order reaction

Fractional order reaction

Solution

Question 7

the energy of the reactants.

the activation energy of the reaction.

the energy of the intermediate.

the energy of the products.

Solution

Question 8

An increase in the reactant concentration

An increase in the temperature

A decrease in pressure

Catalysts

Solution

Question 9

in which reactants do not react

in which one of the reactants is in large excess

whose rate is uniform and not affected by time

whose rate increases with time

Solution

Question 10

$$2, 0$$

$$0, 2$$

$$1, 1$$

$$3, 0$$

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.