Chemistry · Physics

Thermodynamics and Chemical Kinetics

1,132 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 chemistry non-metals dihydrogen fuel dihydrogen as a fuel introduction to hydrogen

Basic principle of hydrogen economy is:

  1. transportation of energy in the form of liquid or gaseous dihydrogen

  2. storage of energy in the form of liquid or gaseous dihydrogen
  3. both $A$ and $B$

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The usage of hydrogen as a low-carbon energy source, such as gasoline as a transport fuel, it is referred to as "Hydrogen economy". The basic principles of Hydrogen economy are:-

(i) Storage of energy in the form of liquid or gaseous dihydrogen.
(ii) transportation of energy in the form of liquid or gaseous dihydrogen.
Thus the answer is both (A) and (B).

Multiple choice physics heat and energy zeroth law of thermodynamics

Two systems in thermal equilibrium with a third system separately are in thermal equilibrium with each other.
The above statement is

  1. First law of thermodynamics

  2. Second law of thermodynamics

  3. Third law of thermodynamics

  4. Zeroth law of thermodynamics
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The given statement is the exact statement of Zeroth law of thermodynamics which deals with thermal equilibrium.

Multiple choice physics heat and energy zeroth law of thermodynamics

The variance defined by Zeroth law of thermodynamics is

  1. Temperature

  2. Internal energy

  3. Work

  4. All of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Zeroth Law of Thermodynamics defines temperature as the property that determines whether two systems are in thermal equilibrium.

Multiple choice physics heat and energy zeroth law of thermodynamics

According to Hess's law, the thermal effects of a reaction depends on

  1. Initial and final conditions of the reacting substances

  2. Initial concentration of reactants

  3. Final conditions of the reacting substances

  4. Not on initial and final conditions of the reacting substance
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to Hess law, the thermal effects of a reaction depends upon the initial and final conditions of the reacting substances. It does not depend upon the immediate steps.

Multiple choice

Why are fireworks examples of chemical reactions?

  1. They are made of chemicals.

  2. They change color and require energy.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Chemical reactions are characterized by observable changes such as color changes, light emission, or energy release. Fireworks exhibit these traits as the chemicals react.

Multiple choice

Energy can....

  1. change forms

  2. be created

  3. be destroyed

  4. make you hyper
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The law of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another. Therefore, changing forms is the correct description.

Multiple choice

The two MAIN categories of energy

  1. Kinetic and Potential

  2. Thermal and Physical

  3. Kinetic and thermal

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In physics, energy is broadly categorized into potential energy (stored energy) and kinetic energy (energy of motion). All other forms of energy are typically variations or combinations of these two.

Multiple choice determination of atomic and isotopic mass some basic concepts of chemistry chemistry

A system undergoes a process in which the entropy change is $+5.51J{K}^{-1}$. During the process, $1.50kJ$ of heat is added to the system at $300K$. The correct information regarding the process is

  1. the process is thermodynamically reversible

  2. the process is thermodynamically irreversible

  3. the process may or may not be thermodynamically reversible

  4. the process must be isobaric
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For a reversible process, delta S = q_rev / T. Here, q/T = 1500 J / 300 K = 5 J/K. Since the actual entropy change (5.51 J/K) is greater than q/T (5 J/K), the process is irreversible.

Multiple choice limitations of bohr model and explanation of bohr's second postulate by matter waves bohr's model atoms atomic nuclei physics

Maximum energy is evolved during which of the following transitions?

  1. $n=1$ to $n=2$
  2. $n=2$ to $n=6$
  3. $n=2$ to $n=1$
  4. $n=6$ to $n=2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When transition is from upper state to lower state, the energy is evolved.
Energy is emitted only when an electron jumps from an outer stationary orbit of energy ${ E } _{ 2 }$ to inner stationary orbit of energy ${ E } _{ 1 }$. The energy emitted $E={ E } _{ 2 }-{ E } _{ 1 }$
In given options only (C) and (D) are practicable.
In option (C),
$E=-Rhc\left( \dfrac { 1 }{ { 1 }^{ 2 } } -\dfrac { 1 }{ { 2 }^{ 2 } }  \right) $
     $=-\dfrac { 3 }{ 4 } Rhc$
In option (D),
$E=-Rhc\left( \dfrac { 1 }{ { 2 }^{ 2 } } -\dfrac { 1 }{ { 6 }^{ 2 } }  \right) $
    $=-\dfrac { 2 }{ 9 } Rhc$
Thus, maximum energy is evolved in option (C).
Note: The process in which absorption of energy by an electron takes the electron from an inner orbit to some outer orbit of higher energy is called excitation.

Multiple choice chemistry chemical equilibrium equilibrium in physical processes introduction to equilibrium chemical equilibrium and acids-bases

An equilibrium expression may be forced to completion by:

  1. adding a catalyst

  2. increasing the pressure

  3. increasing the temperature

  4. removing the products from the reaction mixture as they are formed

  5. decreasing the reactant concentration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

According to Le-chatelier principal reaction moves in forward direction if we remove products with time.so removing the products from the reaction mixture as they are formed may be forced to completion of an equilibrium expression.

Multiple choice chemistry chemical equilibrium equilibrium in physical processes introduction to equilibrium chemical equilibrium and acids-bases

An increase in pressure will change the equilibrium by:

  1. shifting to the side where a smaller volume results

  2. shifting to the side where a larger volume results

  3. favoring the endothermic reaction

  4. favoring the exothermic reaction

  5. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

An increase in pressure will change the equilibrium by shifting to the side from higher number of moles to lower number of moles.