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 physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

Burning of a meteorite in the earth's atmosphere is an example of change of :

  1. heat energy into kinetic energy

  2. kinetic energy into heat energy

  3. kinetic energy into potential energy

  4. potential energy into heat energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A meteorite has both potential and kinetic energy before entering earth's atmosphere. As it enters and fall towards the surface of earth, frictional heating occurs which is caused by collision with the molecules in the atmosphere which reduces its velocity. Hence the kinetic energy decreases, which is converted into heat energy. Potential energy is continuously decreasing being converted to kinetic energy.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

Buming of a meteorite in the Earth's atmosphere is an example of change of:

  1. heat energy into kinetic energy

  2. kinetic energy into heat energy

  3. kinetic energy into potential energy

  4. potential energy into heat energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

when meteorite falls its potential energy is converting into kinetic energy and when it enters earth atmosphere due to air friction its kinetic energy is reduced but potential energy is also decreasing as its height is decreasing , so we can conclude that its first potential energy converts to kinetic energy and then kinetic energy converts to heat energy.

so best possible answer is option B.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

What are the various energy transformations that occur when you are riding bicycle?

  1. Muscular $\rightarrow$ Kinetic $\rightarrow$ Heat
  2. Potential $\rightarrow$ Kinetic $\rightarrow$ Heat
  3. Kinetic $\rightarrow$ Heat $\rightarrow$ Sound

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

While paddling a bicycle muscular energy converted to kinetic energy as the bicycle moves.Rotation of wheel create friction causing loss of kinetic energy in the form of heat.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

In case of explosion of a bomb which of the following does not change?

  1. Chemical energy

  2. Total energy

  3. Kinetic energy

  4. Mechanical energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The chemical energy possessed by the bomb after explosion converts into heat energy, sound energy, light energy i.e. into different forms of energy but remains conserved. Hence, total energy of bomb does not change, but kinetic and mechanical energy changes.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

A cyclist free-wheels from the top of a hill, gathers speed going down the hill, apply his brakes and eventually came to rest at the bottom of the hill. Which one of the following energy changes take place?

  1. Potential to kinetic to heat energy

  2. Kinetic to potential to heat energy

  3. Chemical to heat to potential energy

  4. Kinetic to heat to chemical energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Considering ground as zero potential
Initially $E = U + K = U + 0 = U$
Finally $E = U + K = 0 + 0 = 0$
So, initially it had some potential energy, it was converted to kinetic energy by gaining speed, it finally became zero so energy must have been lost as heat while applying brakes.

Multiple choice movement in plants living world of plants - plant physiology biology

When spontaneous process occurs then free energy of a system _______________.

  1. Decreases

  2. Increases

  3. Remains same

  4. Either can decreases or increase
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to the second law of thermodynamics, spontaneous processes in a system at constant temperature and pressure occur with a decrease in Gibbs free energy.

Multiple choice evs how to save fuel define fossil fuels conservation of fuels reason for finishing of materials (resources) fuel and conservation

Energy can neither be created nor be destroyed, but it can be changed from one form to another. This law is known as:

  1. potential energy

  2. kinetic energy

  3. conservation principle

  4. conservation of energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The law of conservation of energy states that the total energy of an isolated system remains constant, it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed from one form to another.

For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If one adds up all the forms of energy that were released in the explosion, such as the kinetic energy of the pieces, as well as heat and sound, one will get the exact decrease of chemical energy in the combustion of the dynamite.
 Classically, conservation of energy was distinct from conservation of mass; however, special relativity showed that mass could be converted to energy and vice versa by E = mc2, and science now takes the view that mass–energy is conserved.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

In view of the signs of $\Delta _{r}G^{0}$ for the following reactions :
$PbO _{2} +Pb \rightarrow 2PbO, \Delta _ {r}..G..^{0},0$
$SnO _{2} +Sn \rightarrow 2SnO, \Delta _ {r}..G..^{0},0$

  1. For lead +2, for tin +2

  2. For lead +4, for tin +4

  3. For lead +2, for tin +4

  4. For lead +4, for tin +2
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice chemistry chemical thermodynamics system and surroundings introduction to thermodynamics basics of thermodynamics

An isolated system is one which neither shows an exchange of _nor _with surroundings.

  1. heat, mass

  2. heat, temperature

  3. temperature, mass

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Heat, mass

In physical science, an isolated system is either 

(1) a thermodynamic system which is completely enclosed by walls through which can pass neither matter nor energy, though they can move around inside it; or 

(2) a physical system so far removed from others that it does not interact with them.

Hence, option A is correct.
Multiple choice chemistry chemical thermodynamics system and surroundings introduction to thermodynamics basics of thermodynamics

For a reaction to be spontaneous in neither direction, which of the following is/are correct regarding the closed system?
(1) ${ \left( \Delta { G } \right)  } _{ T,P }=0$
(2)${ \left( \Delta { G } \right)  } _{ T,P }< 0$
(3) ${ \left( \Delta { G } \right)  } _{ U,V }=0$
(4) ${ \left( \Delta { G } \right)  } _{ U,V }>0$
Codes:

  1. 1,2,3 are correct

  2. 1 and 2 are correct

  3. 2 and 4 are correct

  4. 1 and 3 are correct
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$\text{For spontaneous in neither direction:}$

(1) ${ \left( \Delta { G } \right)  } _{ T,P }=0$
(3) ${ \left( \Delta { G } \right)  } _{ U,V }=0$
$\text{is correct.}$

Multiple choice chemistry chemical thermodynamics system and surroundings introduction to thermodynamics basics of thermodynamics

Select the state functions among the following:

  1. temperature

  2. entropy

  3. work

  4. enthalpy
Reveal answer Fill a bubble to check yourself
A,B,D Correct answer
Explanation

State function is defined as a system that depends upon the initial and final positions,

so temperature , entropy and enthalpy depends upon the initial and final state, so they are state function but work depends upon the area of PV curve.