Physics

Thermal Properties of Matter

302 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 chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

The pH of pure water at 25°C and 35°C are 7 and 6 respectively. The heat of formation  of water from ${H^ - }$  and $O{H^ - }$ will be :

  1. -77.11

  2. -84.55

  3. -92.36

  4. -66.25
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The auto-ionization of water is H2O <-> H+ + OH-. The heat of formation is related to the change in equilibrium constant (Kw) with temperature. The value -77.11 kJ/mol is the standard enthalpy change for this process.

Multiple choice physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

On heating water from $0^0 C$ to $100^0 C$ its volume 

  1. Increases at each $^0 C$
  2. First increase till $4^0 C$ and then decreases
  3. First decrease till $4^0 C$ and then increases

  4. Remains same
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Water exhibits anomalous expansion. Its density is maximum at 4 degrees Celsius, meaning its volume is minimum at that temperature. Thus, as it heats from 0 to 4 degrees, it contracts (volume decreases), and from 4 to 100 degrees, it expands (volume increases).

Multiple choice chemistry energetics and thermochemistry bond energies and enthalpy changes bond enthalpies enthalpies for different types of reactions

A vessel contains 100 litres of a liquid x. Heat is supplied to the liquid in such a fashion that, heat gives a change in enthalpy. The volume of the liquid increases by 2 litres. If the external pressure is one atm, and 202.6 Joules of heat supplied, then [U $\rightarrow$ total internal energy] :

  1. $\Delta U=0, \Delta H=0$
  2. $\Delta U=+202.6 J, \Delta H=+202.6 J$
  3. $\Delta U=-202.6 J, \Delta H=-202.6 J$
  4. $\Delta U=0, \Delta H=+202.6 L $
Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice chemistry hard water and soft water heavy water study of heavy water hydrogen and its compounds

Heavy water $(D _{2}O)$ freezes at:

  1. $0^\circ C$
  2. $-3.8^\circ C$
  3. $0.8^\circ C$
  4. $3.82^\circ C$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Freezing point of heavy water is $3.82^oC$. Heavy water is a form of water that contains a larger than normal amount of the hydrogen isotope deuterium, rather than the common hydrogen-$1$ isotope that makes up most of the hydrogen in regular water.

Multiple choice various types of barometer fluids physics

An aluminum can of cylindrical shape contains $V _{0}\ cm^{3}$ of water. The area of the linear cross-section of the can is $A _{0}\ cm^{2}$. (All measurement refer to $T _{0}^\circ C$). Find the rise in the water level, if the temperature increases to $T _{1}C(T _{1}^\circ C > T _{0}$) $\alpha _{Al}$ and $\gamma _{water}$ are given

  1. $\dfrac { { V } _{ 0 }\left( { T } _{ 1 }-{ T } _{ 0 } \right) \left( { \gamma } _{ w }-2{ \alpha } _{ Al } \right) }{ { A } _{ 0 } } $
  2. $\dfrac { { V } _{ 0 }\left( { T } _{ 1 }-{ T } _{ 0 } \right) \left( { \gamma } _{ w }-2{ \alpha } _{ Al } \right) }{ {2A } _{ 0 } } $
  3. $\dfrac { { V } _{ 0 }\left( { T } _{ 1 }-{ T } _{ 0 } \right) \left( { \gamma } _{ w }-2{ 3\alpha } _{ Al } \right) }{ { A } _{ 0 } } $
  4. $\dfrac { { V } _{ 0 }\left( { T } _{ 1 }-{ T } _{ 0 } \right) \left( { \gamma } _{ w }-2{ 3\alpha } _{ Al } \right) }{ { 2A } _{ 0 } } $
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The volume of water at T1 is V1 = V0(1 + gamma_w * dT). The area of the can at T1 is A1 = A0(1 + 2 * alpha_Al * dT). The new height h1 = V1 / A1. The rise in level is h1 - h0 = (V0/A0) * [(1 + gamma_w * dT) / (1 + 2 * alpha_Al * dT) - 1]. Using binomial approximation (1+x)^-1 approx 1-x, this simplifies to (V0/A0) * dT * (gamma_w - 2 * alpha_Al).

Multiple choice botany photosynthesis modern concept of photosynthesis photosystems photosynthesis in higher plants

Water has high specific heat due to

  1. Its dipole nature

  2. Smaller angle between hydrogen atoms and oxygen atom

  3. Hydrogen bonds amongst molecules

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Water has high specific heat due to hydrogen bonds amongst molecules. Due to high specific heat, water minimizes changes in temperature. Hydrogen bonds are broken when it absorbs heat. Similarly, hydrogen bonds are formed when water releases energy in the form of temperature. This decreases the temperature of water.

Thus, the correct answer is option C.

Multiple choice chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

Specific heat of water is:

  1. very low

  2. medium

  3. sometimes high and sometimes low

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

The specific heat of water is $1$ $calorie/gm^oC=4.186$ $Joule/gm^oC$, which is higher than another common substance.

So, none of the above statement is true for specific heat of water.

Multiple choice chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

At what temperature ,water have maximum density?

  1. $0^oC$
  2. $4^oC$
  3. $30^oC$
  4. $25^oC$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water exhibits anomalous expansion; it contracts as it cools until it reaches 4 degrees Celsius, after which it begins to expand as it cools further toward freezing. Therefore, its density is highest at 4 degrees Celsius.

Multiple choice chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

Water is cooled from $4^{\circ}C$ to $0^{\circ}C$. It will:

  1. contract

  2. expand

  3. first contract, then expand

  4. first expand, then contract
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water is cooled from $4^{\circ}C$ to $0^{\circ}C$. It is called "Anomalous expansion of water", i.e. The expansion between 4 and 0 is due to the formation of larger clusters in the water molecules.
When water molecules go from $4^{\circ}C$ to $0^{\circ}C$, they are forming groups in small lattices, what increases volume and decreases density. When water ices, then all their molecules are forming that lattice, as mineral crystals do, with the volume expanded.
Above $4^{\circ}C$, thermal expansion sets as thermal vibrations of the OH bonds of water becomes more vigorous, tending to shove the molecules farther apart and water expands.
As a result of this water at $4^{\circ}C$ is denser than that at $0^{\circ}C$. This causes floating of ice on water during winter. Bursting of pipes is also due to anomalous expansion.
Thus, Option B is correct.

Multiple choice chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

A teacher one day pointed out to his students the peculiar fact that water is a unique liquid that freezes exactly at $0^oC$ and boils exactly at $100^oC$. He asked the students to find the correct statement based on this fact.


Which of the statements is true regarding the above fact?

  1. Water dissolves anything however sparingly the dissolution may be.

  2. Water is a polar molecule.

  3. Boiling and freezing temperatures of water were used to define a temperature scale.

  4. Liquid water is denser than ice.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Option (C) is correct.
Boiling and freezing temperatures of water were used to define a temperature scale.The scaling of zero degree centigrade is based on this fact.