Content Curator
Thermal properties of matter are those properties that are related to its conductivity of heat.
- The property of matter which responds to heat is known as the thermal property of matter.
- It is related to the conductivity of heat.
- Thermal properties are displayed by the objects when heat is made to pass through them.
- The thermal properties of a matter determine the reaction of the object when it is exposed to heat fluctuations.
- Different objects respond differently to the effect of heat.
The major components of the thermal properties of matter are:
| Table of Content |
Key Terms: Thermal properties of matter, Matter, Thermal expansion, Heat capacity, Thermal conductivity, Thermal stress, Specific heat capacity, Calorimetry, Temperature
What is Matter
[Click Here for Sample Questions]
Anything that has mass or occupies space in the universe is known as matter. There are five properties of matter namely
- Mechanical,
- Chemical,
- Thermal,
- Dimensional, and
- Physical properties.
Here we will focus on discussing the thermal properties of matter.
Heat Capacity
[Click Here for previous Years Questions]
The quantity of heat required to change the temperature of the matter by 1 degree is known as the heat capacity of a material.
- The temperature is expressed in kelvin or Celsius and the amount of heat is represented in calories or joules.
- Specific heat capacity or molar heat capacity is used to calculate the heat capacity of the matter with the given dimension.
Linear expansion is the situation when change is taking place in one dimension or dimensional.
Read More: Latent Heat of Water
Thermal Expansion
[Click Here for Sample Questions]
The change in the volume, area, and shape when heat is passed through a material I recognized as the thermal expansion property of the material.
The expansion of the railway tracks due to extreme heat which leads to accidents is an example of thermal expansion.
Thermal Conductivity
[Click Here for Sample Questions]
This property is related to the conductivity of heat.
- The amount of heat conducted by the material is directly proportional to the conductivity of the material.
- Not all objects have the capacity to conduct heat through their bodies.
- Insulators are such objects which do not have the property to conduct heat through their body.
The thermal conductivity of some of the materials are listed below:
| Materials | Thermal Conductivity | |
|---|---|---|
| Metals | Silver | 406 |
| Copper | 385 | |
| Mercury | 8.3 | |
| Non-Metals | Insulating brick | 0.15 |
| Glass | 0.8 | |
| Water | 0.8 | |
| Gases | Air | 0.024 |
| Argon | 0.016 | |
| Hydrogen | 0.14 |
Thermal Stress
[Click Here for previous Years Questions]
Thermal stress is the stress on the body due to thermal contraction or expansion.
- The explosion of materials happens due to thermal stress which is dangerous.
- The cracks on the truck tyres are caused by the resulting thermal stress.
- Trucks on high speed produce Heat which is caused by the friction of the truck tyres and the road surface.
Read More:
Calorimetry
[Click Here for Sample Questions]
When no heat is transferred between the object and the surroundings, the object is said to be isolated.
- Heat is transferred from a portion of high temperature to a portion of low temperature when the isolated system is charged with different temperatures in different portions.
- A balance is created between the heat gained by the portion of lower temperature and the heat lost by the portion of higher temperature.
- The measurement of heat is known as calorimetry.
- When a body of high temperature and low temperature comes in contact with each other, heat is lost by the body of high temperature which is equal to the heat gained by the body of low temperature.
- The calorimeter is the device to measure heat.
Relation of temperature and water at 1 atm pressure
Important Formulae
-
When Q= the heat capacity in J
m = mass in g
c = specific heat in J.K -1
ΔT = change in temperature
Then,
Q= m c ΔT
-
When m = mass, ΔQ = Heat required to change the temperature, and ΔT = Changed temperature
Then,
Specific heat (s) = m ΔQΔT
-
T1 = Temperature of the surrounding medium
T2 = temperature of the body
K = thermal conductivity
Then,
dQ / dt = k ( T2 – T1)
-
Relation of Celsius temperature (tc) and Fahrenheit temperature (tf):
tf = (9/5) tc + 32
-
Relation between pressure (p), volume (v), and absolute temperature (T):
Pv = µRT
- Linear expansion (ΔL) = αLΔT
Where, ΔL = Change in length
ΔT = Change in temperature
α = coefficient of linear expression that changes slightly with temperature
Read More:
| Related Articles | ||
|---|---|---|
| Coefficient of Linear Expansion | Working of boiler | Temperature measurement thermometer |
Things to Remember
- Thermal properties of matter refer to the state of matter in the presence of thermal energy.
- The four major components of thermal properties of matter are heat capacity, thermal expansion, thermal conductivity and thermal stress.
- The formula for heat capacity: Q = mc\(\bigtriangleup\)T
- The formula for linear expansion is: \(\bigtriangleup L = \propto L \bigtriangleup T\)
- The three methods of heat transfer are conduction, convection and radiation.
Previous years Questions
- Water is heated from 0∘C to 10∘C. then its volume
- A metallic bar of coefficient of linear expansion 10−5K−1 is heated from 0∘C to 100∘C. The percentage increase in its length is
- The ratio of the energy radiated by A to that by B is
- If αα be the coefficient of linear expansion of the rod, then the value of ΔIIΔII is
- When the temperature of the liquid becomes 40∘C, the rate of heat loss is J s−1 is
- the temperature difference across the wall is 36∘C. The temperature difference across layer A is
- A uniform copper rod of 50cm50cm length is insulated on the sides, and has its ends exposed to ice and steam respectively.
- Certain amount of heat is given to 100 g of copper to increase its temperature by 21 ∘C.
- when the surrounding temperature is 15∘C, is
- If the source supplies 40 kJ of heat energy, the work done by the engine is
- The gas cause Green House Effect is
- A body cools from 50?C to 49?C in 5 seconds. How long will it take to cool from 40?C to 39?C?
- The final temperature of the mixture is
- The mass of the steam required for this purpose is
- If now both the rods are joined in parallel, then the same amount of heat △O△O will flow in :
Sample Questions
Ques. An iron ring is attached to the rim of a wooden wheel of a bullock cart by a blacksmith. The diameter of the rim is 5.243m and the diameter of the iron ring is 5.231m at 27 degrees Celsius. What should be the temperature of the ring to fit the rim of the wheel? (3 marks)
Ans. T1 = 27 degree celsius
LT1 = 5.231m
LT2 = 5.234m
So,
LT2 = LT1 [1 + α1 (T2 – T1)]
5.243m = 5.231m [1 + 1.2010-5 K -1 (T2 – 27 Δc)
Or, T2 = 218oc
Ques. A container contains a mixture of 0.15kg of ice at 0oc and 0.30kg of water at 50oc. the resulting temperature is 6.7oc. calculate the heat of fusion of ice. (3 marks)
Ans. Heat lost in water = msw( ef - el )w
= (0.30 kg) (4186 J kg-1 k -1 ) (50.0oc – 6.7 oc )
= 54376.14 J
Heat required to melt ice = m2L1 = ( 0.15kg) L1
Heat required to increase temperature to ice water to final temperature = m1sw (ef - e1)1
= (0.15 kg) (4186 J Kg-1 k-1 ) (6.7 oc -0oc)
= 4206.93 J
Heat gained = heat lost
54376.14 J = (0.15 Kg )Lf + 4206.93 J
L1 = 3.34105 J kg-1
Ques. When at room temperature at 20oc, a hot pan cools from 94oc to 86oc in 2 mins. How long will it take to cool from 71oc to 69oc? (3 marks)
Ans. The pan cools 8oc in 2 mins under the condition that the average temperature of 94oc and 86oc is 90oc which is 70oc above the room temperature.
change in temperature time K T (where k = a positive constant depending upon the area and nature of the surface of the body)
8oc2 mins = K (70oc)
The average of 69oc and 71oc is 70oc, which is 50oc above room temperature, K does not change.
2otime = K (50oc)
Dividing the two equations, we have
8c2 min2 c/time = k (70c)k (50c)
Time = 0.7 mins
= 42 sec
Ques. How are the properties of materials classified? (3 marks)
Ans. The properties of materials are
- Thermal properties of materials
- Mechanical properties of materials
- Dimensional properties of materials
- Chemical properties of materials
- Physical properties of materials
Ques. What are the major components of thermal properties? (3 marks)
Ans. The following are the major components of thermal properties
- Heat capacity
- Thermal stress
- Thermal Expansion
- Thermal conductivity
Ques. Materials with high thermal conductivity conduct less heat. State True or False. (1 mark)
Ans. False, High thermal conductivity materials will conduct more heat.
Ques. What is the formula to calculate the heat capacity? (1 mark)
Ans. The formula of heat capacity is Q = m c ΔT
Ques. What is thermal stress? (2 marks)
Ans. Thermal stress is the stress that a body experiences as a result of contraction or thermal expansion.
Ques. What is the principle of calorimetry? (2 marks)
Ans. The calorimetric principle demonstrates the law of conservation of energy, which states that the total heat lost by the hot body equals the total heat acquired by the cool body.
Do Check Out:
Comments