Physics

Thermal Properties of Matter

274 Questions

Thermal properties of matter examine how substances react to heat, covering concepts like temperature, specific heat, and phase changes. This topic is regularly tested in the physics and general science sections of competitive exams. Use this collection to solve numericals on heat transfer, thermal equilibrium, and melting points.

Heat transfer and mixingMelting and freezing pointsThermal expansion and densityTriple point of waterCarnot cycle applications

Thermal Properties of Matter Questions

Multiple choice

The anomalous expansion of water can be observed in the temperature range of

  1. 0 K to 4 K

  2. 0oC to 4oC

  3. -4oC to 0oC

  4. -4oC to 6oC
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The anomalous expansion of water is an abnormal property of water whereby it expands instead of contracting when the temperature goes from 4oC to 0oC and it becomes less dense. The density becomes less and less as it freezes because molecules of water normally form open crystal structures when in solid form.

Multiple choice

The density of water is maximum at

  1. 0 K

  2. 4 K

  3. 4°C

  4. 10°C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As water is cooled from 0oC to 4oC, the anomalous expansion of water takes place due to hydrogen bonding.

Multiple choice

At what temperature is the density of water maximum?

  1. 0°C

  2. 4°C
    • 4°C

  4. 100°C

  5. 50°C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When cooled from room temperature liquid water becomes increasingly dense, as with other substances, but at approximately 4°C (39°F), pure water reaches its maximum density. As it is cooled further, it expands to become less dense.

Multiple choice physics heat and energy zeroth law of thermodynamics

Four cubes of ice at $-10^{o}C$ each one gm is taken out from the refrigerator and are put in $150\ gm$ of water at $20^{o} C$. The temperature of water when thermal equilibrium is attained. Assume that no heat is lost to the outside and water equivalent of container is $46\ gm$. (Specific heat capacity of water $=1\ cal/gm-\ ^{o}C$, Specific heat capacity of fusion of ice $=0.5 cal/gm-\ ^{o}C$, Latent heat of fusion of ice $= 80\ cal/gm$)

  1. $0^{o}C$
  2. $-10^{o}C$
  3. $17.9^{o}C$
  4. $None$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The heat required to warm 4g of ice from -10C to 0C is 20 cal. The heat required to melt 4g of ice is 320 cal. The heat available from 150g of water cooling from 20C to 0C is 3000 cal. Since the available heat is much greater than the heat required to melt the ice, the final temperature will be 0C with some ice remaining.

Multiple choice physics heat and energy zeroth law of thermodynamics

$1\ g$ of ice is mixed with $1\ g$ of steam. At thermal equilibrium, the temperature of the mixture is

  1. $50^{\circ}C$
  2. $0^{\circ}C$
  3. $55^{\circ}C$
  4. $100^{\circ}C$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

1g of steam at 100C releases 540 cal to condense and 100 cal to cool to 0C. 1g of ice at 0C requires 80 cal to melt. The steam has far more energy than needed to melt the ice, so the mixture will reach 100C.

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

At 373 K, steam and water are in equilibrium and $\Delta H$ = 40.98 kJ $mol^{-1}$.What will be  $\Delta S$ fro conversion of water into steam?
$H _2O _{(l)} \rightarrow H _2O _{(g)}$

  1. 109.8 J $K^{-1}mol^{-1}$
  2. 31 J $K^{-1}mol^{-1}$
  3. 21.98 J $K^{-1}mol^{-1}$
  4. 326 J $K^{-1}mol^{-1}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The given reaction is :-

${ H } _{ 2 }O\left( l \right) \longrightarrow { H } _{ 2 }O\left( g \right) $
So, we have
       $\triangle Svap=\dfrac { \triangle Hvap }{ Tb } $
                     $=\dfrac { 40.98\times 1000 }{ 373 } =109.8{ JK }^{ -1 }{ mol }^{ -1 }$

Multiple choice chemistry hydroxy compounds and ethers physical properties of phenol physical properties of alcohols and phenols organic compounds with functional group containing oxygen (part-1)

Melting point of phenol is :

  1. $53^0C$
  2. $43^0C$
  3. $33^0C$
  4. $23^0C$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pure phenols are generally colorless solids or liquids. Phenols (molecular weight $=94$) have the relatively low melting point. So generally exist in liquid form above room temperature.

its melting point is $43^0C$.

Multiple choice physics structure of earth electricity from water energy hydro electricity hydro energy

The minimum height required to convert the stored potential energy of water into electric energy is ____.

  1. $54\ M$
  2. $34\ M$
  3. $100\ M$
  4. $5\ M$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The minimum height required to convent the stored potential energy of water into electric energy is $34\ M$ between the turbine and free energy of water in reservoir.

Multiple choice physics temperature and heat application of various thermometric scales different types of thermometers measuring temperature

On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are $39^o$W and $239^o$W respectively. What will be the temperature on the new scale, corresponding to a temperature of $39^o$C on the Celsius scale ?

  1. $78^o$W
  2. $117^o$W
  3. $200^o$W
  4. $139^o$W
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The scale is linear: W = m * C + c. 0C = 39W, 100C = 239W. Slope m = (239-39)/100 = 2. W = 2 * C + 39. For C = 39, W = 2 * 39 + 39 = 78 + 39 = 117.