CHEMICAL KINETICS
The rate at which a substance reacts depends on its
- Molecular mass
- Atomic mass unit
- Atomic mass
- Active mass
Active mass
The branch of chemistry which deals with the ate and mechanism of a reaction is called _____ .
- Chemical kinetics.
- Classical thermodynamics
- Wave mechanism
- Photochemistry
Chemical kinetics
The change in the concentration of the reactant or product per unit time is called
- Rate of reaction
- Molecularity of the reaction.
- Rate constant
- Order of the reaction
Rate of reaction
Usually the rate of the reaction is expressed as
- mol dm-3
- mol2 dm-2 s-1
- mol dm-2 s-1
- mol dm-3 s-1
mol dm-3 s-1
Chemical kinetics is helpful and used to study
- Mechanism of reaction
- Effect of temperature on reaction rate
- Rate of reaction
- All of A, B, and C
All of A, B, and C
The reaction in which the rate independent of concentration is called ____ .
- Zero order
- First order
- Second order
- Third order
Zero order
The Arrhenius equation accounts for the rate of chemical reaction in terms of?
- Activation energy
- Molecularity of reaction
- Order of reaction
- Physical state
Activation energy
The dimension for first order rate constant is
- s
- s mol-1
- mol-1 S-1
- s-1
s-1
The rate constant of a reaction depends on
- Concentration of reactants
- Concentration of products
- Temperature
- Pressure
Temperature
The rate constant of a reaction has same units as the rate of the reaction. The reaction is of
- Zero order
- First order
- Second order
- Third order
Zero order
The rate constant for 3rd order reaction has the dimension of which of the following?
- mol-2 s-1
- I-1 mol-1 s-1
- mol I-1 s-1
- I2 mol-2 s-1
I2 mol-2 s-1
Which factors affect the rate of the reaction?
- Concentration
- Pressure
- Temperature
- All of A, B, and C
All of A, B, and C
For a reaction of the type A+B → Products, It is observed that doubling the concentration of A causes the reaction rate to be four times as great, but doubling the amount of B there is no apparent effect on the rate. The rate equation is
- Rate = k | A |2
- Rate = k | AI | B |
- Rate = k | A |2 | B |
- Rate = k | A |2 | B |2
Rate = k | A |2
Suppose we have a reaction 2A + B → C+D. The rate of the reaction increase eight times when the concentrations of both A and B are doubled. The rate of the reaction increase four times when the initial concentration of only B is doubled. What is the rate expression for the reaction?
- r = k | A |2 | B |
- r = k | A |2 | B |2
- r = k | A | | B |
- r = k | A | | B |2
r = k | A | | B |2
For an elementary reaction 2A + B → C + D The molecularity of the reaction is
- 4
- 3
- 2
- 1
3
A second order rate constant has the dimension of which of the following?
- dm-6 mol2 s-1
- dm³ mol-1 s-1
- dm I-2 s-1
- dm3 mol s-1
dm³ mol-1 s-1
Which is an acceptable value of the molecularity?
- 2.5
- 0
- 2
- 8
2
Which statement about molecularity is not true?
- It cannot be more than 3
- It can be obtained from balanced equation
- It may be or may not be equal to the order of the reaction
- It cannot be fraction
It cannot be more than 3
law is forever is different from the expression of law of mass action
From an elementary reaction of the type A+ 2B → C + D, What is the order of the reaction?
- 2
- 3
- Cannot be determined
- Zero
Cannot be determined
The following mechanism has been proposed for a reaction 2A+B → D+E, A+B→C+D (slow), A+C →E (fast). What is the rate expression for the reaction?
- r = k | A | | B |
- r = k | A |2 | B |
- r = k | A |2
- r = k | A | | C |
r = k | A | | B |
For a chemical reaction A → products, the rat of the reaction doubles when the concentration of A is increased by 4 times. What is the order of the reaction?
- 0.5
- 0
- 2
- 1
0.5
The minimum amount of energy that the ting molecules must possess at the time of collisions in order to produce effective collisions is called________ .
- Free energy
- External energy
- Internal energy
- Activation energy
Activation energy
What is the order of reaction of radioactive decay?
- Zero
- 2
- 1
- 3
Zero
Point out the false statement.
- Rate law is an experimental fact whereas law of mass action is a theoretical in nature
- Order of the reaction is equal to the sum of the exponents of concentration terms in the rate law
- Rate law is more informative than law of mass action
- law is forever is different from the expression of law of mass action
For a hypothetical reaction A+B Products, the rate law is r = k| B || A |2. What is the order of the reaction?
- 2
- 3
- 0
- 1
2
The hydrolysis of methyl acetate reaction of
- Zero order
- Second order
- Third order
- First order
First order
Suppose, CA is the concentration of A at any time and C0A is its concentration at t = 0, then, for a zero-order reaction of the type A→ Products, the rate equation can be written as ______ .
- CA – C0A =0
- CA = C0A – kt
- CA/C0A = k
- CA =C0A – k
CA =C0A – k
In multistep reaction, Which is the slowest step?
- Mechanism step
- Enthalpy determining step
- Rate determining step
- None of A, B, and C
Rate determining step
The half-life period of any first order reaction
- Is independent of the initial concentration
- Is half the specific rate constant
- Is forever the same whatever the reaction
- Is directly proportional to the initial concentration of the reactant
Is independent of the initial concentration
Which methods are/is helpful and used to determine the rate of the reaction?
- Polarimetry
- Conductometry
- Spectroscopy
- All of A, B, and C
Spectroscopy
Which technique is helpful and used to measure absorption of radiation?
- Conductometry
- Polarimetry
- Dilatometry
- Spectrophotometry
Spectrophotometry
For the first-order reaction with rate constant k, the half-life period (initial concentration = a) is equal to
- 1/ka1/2
- 1/ka
- 0.693/ka
- ln2/k
ln2/k
Why catalyst increases the rate of a reaction?
- It provides the necessary energy to the colliding molecules to cross energy barrier
- It provides a different path of lower activation energy
- It decreases the order of the reaction
- It decreases the heat of the reaction
It provides a different path of lower activation energy
Chemical reactions of the type A-ki→B-k2→C are called
- Pseudo chemical reactions
- Consecutive reactions
- Parallel reactions
- Fast reactions
Consecutive reactions
In dilatometric method, the rate of reaction is measured by change in
- Pressure
- Conductance
- Concentration
- Volume
Volume
The rate of reaction between two specific time intervals is called
- Rate constant
- Instantaneous rate
- Average rate
- Rate of reaction
Average rate
The equation for the rate constant is given by k= p Ze-Ea/RT. A chemical reaction will proceed more rapidly if there is a decrease in
- E
- Z
- T
- P
E
The large increase in the rate of a reaction on rise in temperature is due to
- The increase in the number of molecules having more than the threshold energy
- The decrease in mean free path
- The increase in collision frequency
- The lowering of activation energy
The increase in the number of molecules having more than the threshold energy
In the kinetic study of a reaction A → Products A straight line was observed when a graph between time and 1/C2 was plotted, the reaction is
- Second order
- First order
- Zero order
- Third order
Third order
Which is not a true, characteristic of a catalytic reaction?
- The amount and chemical composition of the catalyst remains unchanged after the reaction
- The catalyst shifts the equilibrium position of a reaction in a helpable direction
- The reaction in which products also act as catalysis are called auto-catalysed reactions
- The catalyst does not initiate a chemical reaction
The catalyst shifts the equilibrium position of a reaction in a helpable direction
Which statement is not related to collision theory?
- Molecules must collide with each other to do a chemical reaction
- Collision theory is applicable to liquids only
- Molecules must have proper orientation
- Molecules must possess a minimum amount of energy
Collision theory is applicable to liquids only
The experimental relationship between rate of the reaction and concentration of the reactants is called
- Rate constant
- Law of mass action
- Le-Chatelier’s principle graph
- Rate law
Rate law
A substance which itself is not a catalyst but increases the activity of a catalyst is called
- Inhibitor
- Poison
- Enzyme
- Promoter
Promoter
Which expressions represent the Arrhenius equation?
- k = e-Ea/K
- k = Ae–Ea/RT
- k = Ae–Ea/T
- k = Ae-Ea/R
k = Ae–Ea/RT
Which is true for Enzymes?
- Proteins
- Inorganic compounds
- Moulds
- Microorganisms
Proteins
The maximum value of order of a reaction helpful and used to may be
- 2
- 1
- 4
- 3
4
Which property of the liquid is measured by polarimetry?
- Optical activity
- Transmittance
- Absorbance
- Conductance
Optical activity
The rate constant of first order reaction depends on
- Temperature
- Time
- Catalyst
- Concentration
Temperature
What is the half-life period for zero order reaction?
- Is independent of initial concentration
- Is proportional to initial concentration
- Is inversely proportional to initial concentration
- Is proportional to square of concentration
Is proportional to initial concentration
What is the temperature coefficient of a reaction?
- The specific rate constant at 25°C.
- The rate of a reaction at 25°C
- The ratio of rate constant at two different temperatures differing by 1°C
- The ratio of rate constant at 35 °C and 65. T 25°C
The ratio of rate constant at 35 °C and 65. T 25°C
The half-life period for a zero order reaction.
- t1/2 = k/2a2
- t1/2 = 2k/a
- t1/2 = a2/2k
- t1/2 = a/2k
t1/2 = a/2k
Which metals are usually helpful and used as catalyst?
- Transition metals
- Coinage metals
- Alkaline earth metals
- Alkali metals
Transition metals
The rate constant for the zero order reaction is given by
- k = (C0 – C1)/t
- k = C0/2t
- k = C0/C1
- k= ln [(C0-C₁)/2t]
k = (C0 – C1)/t
When the initial concentration of the reaction is increased 3 times, the half-life period also increases 3 fold. The order of the reaction is
- Two
- Three
- Zero
- One
Zero
The order of reaction of saponification of ethyl acetate is
- One
- Zero
- Two
- Three
Zero
For the first order reaction, the slope of the plot of log[A], verses tis
- -k/2.303
- k
C.–k
- k/2.303
–k
What is the order of reaction, 2H2O2 2H2O+ O2?
- Zero order
- Third order
- Second order
- First order
Second order
For the second order reaction, the slope of the plot of 1/[A]t verses t is
- -k/2.303
- k
- –k
- k/2.303
k
The plot of logk verses 1/T is a linear with a slope
- -Ea/2.303R
- Ea/R
- –Ea/R
- Ea/2.403R
-Ea/2.303R
A plot of log k versus 1/T of a reaction gives a straight line with
- a non-zero intercept and positive slope
- a non-zero intercept and negative slope
- a zero intercept and negative slope
- a zero intercept and positive slope
a non-zero intercept and negative slope
For a first order reaction a plot of log [A] versus time gives a straight line with:
- a zero intercept and positive slope
- a non-zero intercept and negative slope
- a zero intercept and negative slope
- a non-zero intercept and positive slope
a non-zero intercept and negative slope
More Physical Chemistry MCQs
- PHYSICAL CHEMISTRY MCQs
- CHEMICAL AND IONIC EQUILIBRIA MCQs
- NUCLEAR CHEMISTRY MCQs
- CHEMICAL THERMODYNAMICS MCQs
- NANOCHEMISTRY MCQs
- CHEMICAL KINETICS MCQs
- SURFACE CHEMISTRY MCQs
- COLLOIDAL STATE MCQs
- ELECTROCHEMISTRY MCQs
- SPECTROSCOPY MCQs
- SOLUTION CHEMISTRY AND PHASE EQUILIBRIA MCQs
- PHOTOCHEMISTRY AND MOLECULAR SYMMETRY MCQs
- CHEMISTRY MCQs From all subjects of Chemistry