Chemistry · Physics

Thermodynamics and Chemical Kinetics

1,092 Questions

Thermodynamics and chemical kinetics are crucial branches of physical chemistry. This area focuses on energy transformations, reaction rates, equilibrium constants, and catalysts. These topics carry significant weight in competitive science and engineering examinations.

Enthalpy and energyChemical equilibriumEntropy conceptsReaction kinetics and catalysts

Thermodynamics and Chemical Kinetics Questions

Multiple choice

Which of the following statements is/are false?

a. Some chemical substances can be obtained in pure state by the process of crystallisation. b. The product formed when a substance dissolves in a liquid is known as a solution. c. In a chemical reaction, the substances responsible for bringing about a chemical change are called products.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option as this statement is false. In a chemical reaction, the substances responsible for bringing about a chemical change are called reactants.

Multiple choice

Which of the following is not a property of a chemical change?

  1. Changes are temporary and reversible.

  2. Changes are followed by the formation of a new product.

  3. Changes may give out or absorb heat, light or sound.

  4. Changes are followed by the change in state and composition.

  5. Changes may be followed by the change in colour.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option as this is not a property of a chemical change. Changes are permanent and irreversible.

Multiple choice

In the formation of Al2O3 huge amount of energy is released which makes it useful in

  1. Thermite welding

  2. Gas welding

  3. Tungsten inert gas (TIG) welding

  4. Oxy-acetylene welding
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Thermite  welding is process in which fusion is produced by heating with superheated liquid metal and slag resulting from a chemical reaction between a metal oxide and aluminum, with or without the application of pressure. Filler metal, when used, is obtained from the liquid metal.The Thermite Process or Goldschmidt Process is the method of obtaining liquid metal by reduction of the oxide with aluminium powder, when ignited with magnesium ribbon it reacts by producing iron and aluminium oxide at an intensely high temperature approaching 3000 degrees Celsius.It was developed for making welding repairs in situ, such as rail tracks. It was adopted by the army for use in incendiary bombs.

Multiple choice

Which of the following is not studied under physical chemistry?

  1. Energy changes in a reaction

  2. Reaction rate

  3. Effect of electricity on chemical reaction

  4. Percentage composition of each element in a compound
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Physical chemistry focuses on the physical properties and behavior of matter, such as energy, reaction rates, and electrical effects. Percentage composition is typically studied in analytical chemistry.

Multiple choice

In negative deviation from Rault's law:

  1. A-A interactions = B-B interactions = A-B interactions.

  2. A-A interactions = B-B interactions # A-B interactions.

  3. A-B interactions are more than that of A-A and B-B.

  4. A-B interactions are less than A-A and B-B.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

ANS 3.

Multiple choice

Temperature is a measure of ___________.

  1. total kinetic energy of molecules

  2. total potential energy of molecules

  3. average potential energy of molecules

  4. average kinetic energy of molecules
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Temperature is a measure of the average heat or thermal energy of the particles in a substance. Since it is an average measurement, it does not depend on the number of particles in an object. In that sense it does not depend on the size of it. For example, the temperature of a small cup of boiling water is the same as the temperature of a large pot of boiling water. Even if the large pot is much bigger than the cup and has millions and millions more water molecules.

Multiple choice

Chemical changes are __________.

  1. temporary, reversible and a new substance is produced

  2. always accompanied by exchange of light

  3. permanent, irreversible and a new substance is produced

  4. never accompanied by exchange of light and heat energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 factual

Multiple choice

Temperature is a measure of ___________.

  1. total kinetic energy of molecules

  2. total potential energy of molecules

  3. average potential energy of molecules

  4. average kinetic energy of molecules
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Temperature is a measure of the average heat or thermal energy of the particles in a substance. Since it is an average measurement, it does not depend on the number of particles in an object. In that sense it does not depend on the size of it. For example, the temperature of a small cup of boiling water is the same as the temperature of a large pot of boiling water. Even if the large pot is much bigger than the cup and has millions and millions more water molecules.

Multiple choice

Energy can be neither created nor destroyed, but can be changed from one form to another.

Which of the following statements does not support the above conclusion?

  1. When energy in one form disappears, an equivalent amount of energy in other forms appears somewhere.

  2. The law of conservation applies only when the quantity of matter remains the same.

  3. This law is responsible for a passenger in a running bus moving forward suddenly when the bus stops.

  4. When a bus starts, a standing passenger tends to remain firm rather than the squatting passenger.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

No transformation is taking place here.

Multiple choice

Which of the following statements are true regarding a catalyst? I.          It is a substance which increases the rate of reaction. II.         It is a substance which reduces the activation energy. III.        It is a substance which increases the activation energy. IV.       It is a substance which is consumed in the reaction.

  1. I and II

  2. II and III

  3. III and IV

  4. I and IV
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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