ICSE solutions for Physics [English] Class 10 chapter 10 - Specific Heat Capacity and Latent Heat [Latest edition]

What is heat? What is the S. I. unit of heat?

Define the term calorie. How is it related to joule (the S.I. unit of heat)?

Differentiate between heat and temperature.

What are other units of heat? Name and define them.

How is heat capacity of a body related to specific heat capacity of its substance?

State the condition for the flow of heat energy from one body to another.

What are the factors on which the quantity of heat given to a body depends?

m kg of a substance of specific heat capacity s J/kg °C is heated so that its temperature rises from θ₁°C to θ₂°C. Write down the expression for the heat Q supplied.

Name the substance which has maximum specific heat capacity.

Write two advantages of high specific heat capacity of water.

Does the specific heat capacity of a substance depend upon its mass and rise in temperature only?

Write the approximate values of the specific latent heat of fusion of ice.

Write the approximate values of the specific latent heat of vaporization of steam.

The specific latent heat of fusion of ice is 336 J g^-1. Explain the meaning of its statement.

The farmers fill their fields with water in winter. Give reason.

Why is specific heat capacity taken as a measure of thermal inertia?

Explain, why is water sprayed on roads in evening in hot summer?

Explain, why temperature in hot summer, falls sharply after a sharp shower?

Explain, why do sandy soils, get heated up quickly as compared to wet soils?

Explain, why water is considered as best liquid for quenching thirst?

Explain, Why is it advisabile to pour cold water over burns, caused on human body, by hot solids?

Explain, why does a wise farmer water his fields, if forecast is forst?

Explain, why are big tubs of water kept in underground cellars for storing fresh fruit and vegetables in cold countries.

Explain, why is water used as a coolent in motor car radiators?

Differentiate between heat capacity and specific heat capacity.

Define specific latent heat of vaporization of a substance.

Name two factors on which the heat absorbed or given out by a body depends.

Explain why water is used in hot water bottles for fomentation and also as a universal coolant.

Specific heat capacity of substance A is 3.8 J g^-1 K^-1whereas the specific heat capacity of substance B is 0.4 J g^-1 K^-1. Which of the two is a good conductor of heat? How is one led to this conclusion?

If substances A and B are liquids then which one would be more useful in car radiators?
Given: Specific heat capacity’A’ 3.8 J/g /K. Specific heat capacity ‘B’ 0.4 J/g /K.

How is heat capacity of a body related to specific heat capacity of its substance?

A certain amount of heat Q will warm 1 g of material X by 3°C and 1 g of material Y by 4°C. Which material has a higher specific heat capacity?

Give one example where high specific heat capacity of water is used as heat reservoir ?

Give one example where high specific heat capacity of water is used as cooling purposes?

Name a liquid which has the highest specific heat capacity.

Name two factors on which the heat absorbed or given out by a body depends.

An equal quantity of heat is supplied to two substances A and B. The substance A shows a greater rise in temperature. What can you say about the heat capacity of A as compared to that of B?

Is it possible to condense the water formed, back to ice by adding ice at 0°C. Explain with reason.

Define calorimetry ?

What is the principle of Calorimetry?

Give two reasons as to why copper is preferred over other metals for making calorimeters.

Some heat is provided to a body to raise its temperature by 25°C. What will be the corresponding rise in temperature of the body as shown on the Kelvin scale?

If, in a central heating system, steam enters a radiation pipe at 100°C and water leaves the radiation pipe at 100°C, can this radiation pipe heat a room? Give an explanation for your answer.

Ice-cream at 0°C feels colder than water at 0°C. Give reason for this observation.

Give scientific reasons for the following:

Bottled drinks are cooled more effectively when surrounded by lumps of ice than by cold water at 0°.

Write an expression for the heat energy liberated by a hot body.

1 kg of water freezes to form ice at 0°C. What amount of heat is withdrawn?

Why does the heat supplied to a substance during its change of state not cause any rise in its temperature?

What energy change would you Expect to take place in the molecules of a substance when it undergoes:
(i) a change in its temperature?
(ii) a change in itsstate without any change in its temperature?

Ice is more effective in cooling than the ice-water. Explain.

Why does atmospheric temperature fall after hail storm?

1 kg of steam condenses to water at 100°C. How many joules of heat energy is liberated?

What happens to the average kinetic energy of the molecules as ice melts at 0°C?

Why do doctors advise to put a strip of wet cloth on the forehead of a person having high fever (temperature)?

Explain the meaning of the term latent heat. State its S. I. unit.

What happens to the heat supplied to a substance when the heat supplied causes no change in the temperature of the substance?

When 1 g of ice at 0 °C melts to form 1 g of water at 0 °C then, is the latent heat absorbed by the ice or given out by it?

Give one consequence of the high specific latent heat of fusion of ice.

Why does weather become pleasant when it starts freezing in cold countries?

Why water get cooled in a ‘Surahi’ in hot season?

Why are athletes advised to put on extra clothes after competing on event?

Define the term ‘specific latent heat of fusion’ of a substance.

The specific latent heat of vaporisation of steam is 2260 J/g. Comment on this.

Define specific latent heat of vaporization of a substance.

Explain the statement; “The specific latent heat of vaporization of wafer is 2260 × 10³ J/kg”.

Why do we feel much comfortable when we sit under a moving fan especially when our body is sweating?

Explain, why no tracks are left on the ice during ice skating?

Why does evaporation causes cooling and why is water used in hot water bottles?

What do you understand by the ‘latent heat of vaporization’ of a substance?

Explain the meaning of greenhouse effect.

Name the greenhouse gases.

How does green house effect help in keeping the temperature of earth’s surface suitable for living of human beings?

Give three reasons for the increase of green house gases.

What is meant by global warming?

State the effect of enhancement of green house effect.

How will rise in sea level affect population in coastal countries?

What impact will global warming have on the health of the affected population?

State two impacts of global warming on the life on earth.

State three ways to minimize the global warming.

What impact will global warming have on the lakes and oceans?

Explain briefly, how you would determine the specific heat capacity of a liquid?

Describe a method to determine the specific heat capacity of a solid (say, a piece of copper).

State two advantages of the high specific latent heat capacity of steam, which is about 226 × 10⁴ J/kg?

Discuss how high specific heat capacity of water helps in formation of land and sea breeze.

Will the value of specific heat’capacity and specific latent heat of a substance change if the scale is °F instead of °C?

What is the principle of Calorimetry?

State the main precautions to be taken in finding the latent heat of steam.

Derive an expression for the amount of heat given out or taken up, when its temperature falls or rises by t°C.

A substance is in the form of a solid at 0°C. The amount of heat added to this substance and the temperature of the substance are plotted on the following graph:

If the specific heat capacity of the solid substance is 500 J/kg °G, find from the graph, the mass of the substance.

A piece of ice is heated at a constant rate. The variation of temperature with heat input is shown in the graph below:

(i) What are represented by AB and CD?
(ii) What conclusion can you draw regarding the 110°c nature of ice from the above graph?

What observation you will record and how will you determine the specific latent heat of fusion of ice?

The temperature of a lead piece of mass 400 g rises from 20°C to 50°C when 1560 J of heat is supplied to it. Calculate: Heat capacity of lead piece.

The temperature of a lead piece of mass 400 g rises from 20°C to 50°C when 1560 J of heat is supplied to it. Calculate Specific heat capacity of lead.

63.2 g of copper at 50°C can just melt 3.8g of ice. If the specific latent heat of ice is 336 J/g, find the specific heat capacity of copper.

Water falls from a height of 50 m. Calculate the rise in the temperature of water when it strikes the bottom.
(g = 10 ms^-2; Specific heat capacity of water = 4200 J / kg°C)

50 g of metal piece at 27°C requires 2400 J of heat energy so as to attain a temperature of 327°C . Calculate the specific heat capacity of the metal.

How much heat energy is released when 5 g of water at 20° C changes to ice at 0° C?
[Specific heat capacity of water = 4.2 J g^-1 ° C^-1 Specific latent heat of fusion of ice = 336 J g^-1]

A. hot solid of mass 60 g at 100°C is placed in 150 g of water at 20° C. The final steady temperature recorded is 25°C. Calculate the specific heat capacity of the solid. [Specific heat capacity of water = 4200 J kg^-1 °C^-1]

Find the time taken by a 500 W heater to raise the temperature of 50 kg of material of specific heat capacity 960 J kg^-1K^-1, from 18°C to 38° C. Assume that all the heat energy supplied by the heater is given to the material.

A piece of iron of mass 2.0 kg has a thermal capacity of 966 J/°C. What is its specific heat capacity in S.I. units?

A vessel of negligible heat*capacity contains 40g of ice in it at 0°C, 8g of steam at 100°C is passed into the ice to melt it. Find the final temperature of the contents of the vessel.
(Specific latent heat of vaporization of steam = 2268 J/g, specific latent heat of fusion of ice = 336 J/f and specific heat capacity of water = 4.2 J/g°C)

Calculate the amount of heat released when 5.0 g of water at 20°C is changed into ice at 0°C.
(Specific heat capacity of water = 4.2 J/g°C
Specific latent heat of fusion of ice = 336 J/g)

Calculate the heat energy that will be released when 5.0 kg of steam at 100°C condenses to form water at 100°C. Express your answer in S.I. unit. (Specific latent heat of vaporization of steam is 2268 kj/kg.)

200 g of hot water at 80°C is added to 300 g of cold water at 10 °C. Calculate the final temperature of the mixture of water. Consider the heat taken by the container to be negligible. [specific heat capacity of water is 4200 J kg^-1 °C^-1]

An electric immersion heater is rated 1250 W. Calculate the time in which it will heat 20 kg of water at 5°C to 65°C.

A piece of iron of mass 2.0 kg has a heat capacity of 966 J K^-1. Find heat energy needed to warm it by 15°C.

Some hot water was added to three times its mass of cold water at 10°C and the resulting temperature was found to be 20°C. What was the temperature of the hot water?

Derive an expression for finding out the specific heat capacity of a body (solid) from the readings of an experiment given below:

(i) Mass of empty calorimeter (with stirrer) = m₁ gm

(ii) Mass of the metal piece = M gm

(iii) Mass of colorimeter and water = m2 gm

(iv) Initial temperature and water = t₁°C

(v) Temperature of hot solid (metal piece) = t₂ °C

(vi) Final temperature of the mixture = t°C

(vii) Specific heat of calorimeter = 0.4 J gm / °C

A body ‘A’ of mass m₁ of a substance of a specific heat capacity c₁ at a temperature θ₁ is mixed with a body ‘B’ of mass m₂ of other substance of specific heat capacity c₂ at a lower temperature θ₂. Deduce the expression for the temperature of the mixture. State the assumption made, if any.

A copper calorimeter of mass 50g contains 100g of water at 20°C. A metallic piece of mass 250 g is heated to 100°C and is then dropped into the calorimeter. The contents of the calorimeter are well stirred and its final highest temperature is recorded to be 28 °C. If the specific heat capacity of water is 4.2 J/g°C and of copper is 0.4 J/g°C, find:
(i) the heat gained by water,
(ii) the heat gained by calorimeter,
(iii) total heat supplied by the metal piece, and
(iv) the specific heat capacity of metal.

A mass of 40g of brass of specific heat capacity 0.85 Jg^-1 K^-1 is heated in an oven and then quickly transferred into 240g of water at 30°C in a calorimeter of mass 60g and specific heat capacity 0.4 Jg^-1 K^-1. If the final temperature is 50°C. What was the temperature of the oven?

A Bunsen burner raises the temperature of 500g of water from 10°C to 100°C in 5 minutes. What heat is supplied per second?

40g of ice at 0°C is used to bring down the temperature of a certain mass of water at 60°C to 10°C. Find the mass of water used.
[Specific heat capacity of water = 4200 J kg^-1 °C^-1]
[Specific latent heat of fusion of ice = 336 × 10³ J kg^-1]

250 g of water at 30 °C is present in a copper vessel of mass 50 g. Calculate the mass of ice required to bring down the temperature of the vessel and its contents to 5 °C.
Specific latent heat of fusion of ice = 336 × 10³ J kg^-1
Specific heat capacity of copper vessel = 400 J kg^-1 °C^-1
Specific heat capacity of water = 4200 J kg^-1 °C^-1.

The temperature of 600 g of cold water rises by 15° C when 300 g of hot water at 50° C is added to it. What was the initial temperature of the cold water?

20 g of ice at 0°C is added to 200g of water at 20°C. Calculate the drop in temperature ignoring the heat capacity of the container. (Specific latent heat of ice = 80 cal/g)

Find the final temperature when a mass of 80g of water at 100°C is mixed with a mass of 40g of water at 25°C.

A heater supplies heat at the rate of 800 J/s. Find the time required to convert 50g of ice at -20°C into superheated steam at 140°C.

(Given: Specific heat of ice = 2.1 J/g, latent heat of ice = 340 J/gm, latent heat of steam = 2240 J/gm, specific heat of steam = 2.1 J/gm and specific heat of water = 4.2 J/gm.)

(i) A molten metal weighing 150 g is kept at its melting point 800°C. When it is allowed to solidify at the same temp, it gives out 75000 J of heat. What is the specific heat of the metal?

(ii) If its specific heat capacity is 200 J/kgK? How much additional heat will it give out in cooling to -50°C?

Heat energy is supplied at a constant rate to 100g of ice at 0 °C. The ice is converted into water at 0° C in 2 minutes. How much time will be required to raise the temperature of water from 0 °C to 20 °C? [Given: sp. heat capacity of water = 4.2 J g^-1 °C^-1, sp. latent heat of ice = 336 J g^-1].

50 g of ice at 0°C is added to 300 g of a liquid at 30°C. What will be the final temperature of the mixture when all the ice has melted? The specific heat capacity of the liquid is 2.65 Jg^-1 °C^-1 while that of water is 4.2 J g^-1 °C^-1. Specific latent heat of fusion of ice = 336 Jg^-1.

Calculate the total amount of heat required to convert 100g ice at 0°C to steam at 100°C. 
(Specific latent heat of fusion of ice = 336 J/g, specific latent heat of vaporization of steam = 2260 J/g, specific heat capacity of water = 4.2 J/g°C).

Steam at 100°C is passed over 1000 g of ice at 0°C. After some time, 600 g of ice at 0°C is left and 450 g of water at 0°C is formed. Calculate the specific latent heat of vaporization of steam (Given: specific heat capacity of water = 4200 J/kg°C, specific latent heat of fusion of ice = 336,000 J/kg.)

If there is no Heat loss to the surroundings, the heat released by the condensation of m₁ g of steam at 100°C into water at 100°C can be used to convert m₂ g of ice at 0°C into water at 0°C.

(i) Find:

(a) The heat lost by steam in terms of m₁

(b) The heat gained by ice in terms of m₂

(ii) Form a heat equation find the ratio of m₂ : m₁

Specific latent heat of vaporization of steam = 2268 kJ/kg

Specific latent heat of fusion of ice = 336 kJ/kg

Specific heat capacity of water = 4200 J/kg°C

1 kg of water is contained in a 1.25 kW kettle. Assuming specific heat capacity of water = 4.2 J/g °C and specific latent heat of vaporization = 2260 J/g, calculate:
(i) the time taken for the temperature of water to rise from 25°C to its boiling point,
(ii) the mass of water which evaporates per minute from the boiling water.