TNPSC Chemistry - Chemical Kinetics Catalysis Physical and Chemical Change
Exam Duration: 45 Mins Total Questions : 25
Two reactions with different activation energies have the sane rate at room temperature. Which statement correctly describes the rates of these reaction at the same higher temperatures?
- (a)
The reaction with the greater activation energy will be faster
- (b)
The reaction with the smaller activation energy will be faster
- (c)
The two reaction will have the same rates
- (d)
A prediction cannot be made without more information
Consider the following statements
1. First order chemical reaction takes infinite time to complete.
2. Fractional life period of first order chemical reaction does not depend on reactant concentration.
Which one of the following is correct in respect of the above two statements?
- (a)
Both the statements are true and Statement II is the correct explanation of Statements I
- (b)
Both the statements are true and Statement II is not the correct explanation of Statements I
- (c)
Statements I is true, but Statements II is false
- (d)
Statements I is false, but Statements II is true
The order of photochemical reaction between H2 and Cl2 is
- (a)
zero
- (b)
first
- (c)
second
- (d)
third
Match Column I (Different constants) with Column II (Dimensional quantities) and select the correct answer using the codes given below the Columns.
Column I | Column II |
A. Boltzmann constant | JK-1 |
B. Molal elevation constant | kg K mol-1 |
C. Zero-order reaction rate constant | L mol-1s-1 |
D. Second-order reaction rate constant | mol L-1s-1 |
- (a)
A B C D 1 3 4 2 - (b)
A B C D 4 2 1 3 - (c)
A B C D 4 3 1 2 - (d)
A B C D 1 2 4 3
Assertion (A) A chemical reaction becomes faster at higher temperatures.
Reason (R) At higher temperatures molecular motion becomes more rapid.
- (a)
Both A and B are individually true and R is the correct explanation of A
- (b)
Both A and B are individually true, but R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
Which among the following has been producing/can produce light by a chemical change?
- (a)
Sun
- (b)
Moon
- (c)
Electric bulb
- (d)
Lighting and thunder
Match Column I with Column II
Column I (Process) | Column II (Catalyst) |
A. Manufacture of sulphuric acid by contact process | 1. Fe2O3 + Cr2O3 |
B. Deacon's process for the manufacture of cholrine | 2. Cr2O3 |
C. Hydrogenation of oil | 3. CuCl2 |
D. Manufacture of hydrogen by Bosch's process | 4. V2O5 |
Select the correct answer using the codes given below the Columns.
- (a)
A B C D 1 4 3 2 - (b)
A B C D 2 1 4 3 - (c)
A B C D 3 2 1 4 - (d)
A B C D 4 3 2 1
Pick the wrong statement from the given below.
- (a)
Carbon dioxide reacts with metallic hydroxides to form their carbonates
- (b)
Carbon dioxide dissolves in water to form Carbon acid
- (c)
Carbon dioxide does not react with lime water
- (d)
Carbon dioxide is a green house gas
Which of the following represents a chemical change?
1. Magnetisation of iron.
2. Condensation of liquid.
3. Burning of fuel.
4. Rusting of iron.
select the correct answer using the codes given below
- (a)
1 and 2
- (b)
2 and 3
- (c)
3 and 4
- (d)
1 and 4
In the Haber's process of synthesis of NH3,
- (a)
Mo acts as a catalyst and Fe as a promotor
- (b)
Fe acts as a catalyst and Mo as a promotor
- (c)
Fe acts as inhibitor and Mo as a catalyst
- (d)
Fe acts as promotor
and Mo as auto catalyst
Match Column I with Column II.
Column I (Process) | Column II (Catalyst) |
A. Alcoholic fermentation | 1. Pt |
B. Glucose or fructose C2H5OH | 2. H, +, mineral acid and enzymes |
C. Ostwald process for manufacture of HNO3 | 3. Zymase |
D. hydrolysis of cane sugar | 4. Yeast |
Select the correct answer using the codes given below the Columns
- (a)
A B C D 4 3 1 2 - (b)
A B C D 3 1 2 4 - (c)
A B C D 1 2 4 3 - (d)
A B C D 2 4 3 1
Which one of the following is a chemical process?
- (a)
Distillation of sea (salty) water
- (b)
Crystallisation of impure salt (NaCl)
- (c)
Production of iodine (I2) from sea-weeds
- (d)
Sublimation of iodine (I2)
Which of the following statements regarding the property of hard water is/are correct?
1. Temporary hardness of water is due to the process of soluble magnesium and calcium hydrogen carbonate.
2. Temporary hardness of water can be removed by boiling.
3. Calgon's method is applied to remove temporary hardness of water.
4. Permanent hardness of water is removed by Clark's method.
Select the correct answer using the codes given below
- (a)
1 and 2
- (b)
1,2 and 3
- (c)
3 and 4
- (d)
Only 2
Which among the following is a chemical change?
- (a)
A wet towel dries in the sun
- (b)
Lemon juice added to tea causing its colour to change
- (c)
Hot air rises over a radiator
- (d)
Coffee is brewed by passing steam through ground coffee
Assertion (A) Colloidal solution scatter light while true solution do not.
Reason (R) The particles in the colloidal solution move much slower than that of the true solution.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true, but R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
Consider the following statements
1. Reactions in which heat is released along with the formation of products are called exothermic chemical reactions.
2. Reactions in which energy is absorbed are known as endothermic reactions.
Which of the statements given above is/are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
1 and 2
- (d)
None of these
What is the role of positive catalyst in a chemical reaction?
- (a)
It increases the rate of reaction
- (b)
It decreases the rate of reaction
- (c)
It increases the yield of the products
- (d)
It provide better purity of the products
The temperature at which the catalytic activity of the catalyst is maximum, is called
- (a)
critical temperature
- (b)
room temperature
- (c)
absolute temperature
- (d)
optimum temperature
The activation energy of a reaction is zero. The rate constant for the reaction
- (a)
decreases with decrease of temperature
- (b)
increases with increase of temperature
- (c)
decreases with increase of temperature
- (d)
is nearly independent of temperature
Assertion (A) Lower activation energy faster is the reaction.
Reason (R) If the activation energy of reaction is zero, temperature will have no effect on the rate constant.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true, but R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
Which of the following is a model of enzyme action?
- (a)
Lock and key model
- (b)
Hand and glove model
- (c)
Induced fit model
- (d)
All of the above
An example of an autocatalytic reaction is
- (a)
hydrogenation of oil
- (b)
decomposition of nitroglycerine
- (c)
oxidation of Na2AsO3 in presence of Na2SO3
- (d)
thermal decomposition of KClO3 in presence of MnO2
It is recommended that liquor ammonia bottles be opened after cooling them in ice for sometime. This is because liquor ammonia
- (a)
bring tears to eyes
- (b)
is a mild explosive
- (c)
is a corrosive liquid
- (d)
has a high vapour pressure
In which one of the following situations a chemical reaction does not occur?
- (a)
Common salt is exposed to air
- (b)
Coal is burnt in air
- (c)
Sodium is placed in water
- (d)
Iron is kept in moist air
Enzyme catalysis is an example of
- (a)
induced catalysts
- (b)
auto catalysts
- (c)
heterogeneous catalysts
- (d)
homogenous catalysts