Goyal Brothers Textbook Solutions: Calorimetry

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Calorimetry 
 
Exercise – 1 
Question 1. 
Define calorie. 
Answer: 
CALORIE : “Is the amount of heat energy required to raise the temperature of 1 g of 
water from 14.5 °C to 15.5°C”. 
Question 2. 
State the modern unit of heat energy. How is this unit related to calorie ? 
Answer: 
Modern unit of heat energy is joule 
Relation of joule with calorie : 
1 J = 2.4 calorie 
or 1 calorie = 4 .186 J = 4.2 J (approx) 
Question 3. 
What do you understand by the term thermal capacity ? State its unit is SI system. 
Answer: 
Thermal capacity : “The amount of heat energy required to raise the temperature of a 
given mass of substance through 1°C (1k) is called thermal capacity”. 
Question 4. 
Define specific heat capacity and state its SI and CGS units. 
Answer: 
Specific heat capacity : “Is the amount of heat energy required to raise the temperature 
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Calorimetry 
 
Exercise – 1 
Question 1. 
Define calorie. 
Answer: 
CALORIE : “Is the amount of heat energy required to raise the temperature of 1 g of 
water from 14.5 °C to 15.5°C”. 
Question 2. 
State the modern unit of heat energy. How is this unit related to calorie ? 
Answer: 
Modern unit of heat energy is joule 
Relation of joule with calorie : 
1 J = 2.4 calorie 
or 1 calorie = 4 .186 J = 4.2 J (approx) 
Question 3. 
What do you understand by the term thermal capacity ? State its unit is SI system. 
Answer: 
Thermal capacity : “The amount of heat energy required to raise the temperature of a 
given mass of substance through 1°C (1k) is called thermal capacity”. 
Question 4. 
Define specific heat capacity and state its SI and CGS units. 
Answer: 
Specific heat capacity : “Is the amount of heat energy required to raise the temperature 
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of unit mass of a substance through 1°C or 1K is called specific heat capacity.” 
 
Question 5. 
Is the specific heat capacity of ice greater, equal to or less than water ? 
Answer: 
Specific heat capacity of ice is less than specific heat capacity of water. 
Question 6. 
Explain the following : 
(a) Water is used in hot water bottles for fomentation purposes. 
Answer: 
Water provides heat energy for longer time and does not cool quickly as specific heat 
capacity of water is large. 
(b) Water is used as a coolant in motor car radiators. 
Answer: 
When water is circulated in the pipes, it absorbs more amount of heat from 
surroundings (removes heat) without much rise in its temperature because of its high 
specific heat capacity. 
(c) A wise farmer always waters his fields in the evening, if there is a forecast for frost. 
Answer: 
To save the crops on such cold nights farmers fill their fields with water as water has 
high sp. heat capacity. So water does not allow the temp, in the surrounding area of 
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Calorimetry 
 
Exercise – 1 
Question 1. 
Define calorie. 
Answer: 
CALORIE : “Is the amount of heat energy required to raise the temperature of 1 g of 
water from 14.5 °C to 15.5°C”. 
Question 2. 
State the modern unit of heat energy. How is this unit related to calorie ? 
Answer: 
Modern unit of heat energy is joule 
Relation of joule with calorie : 
1 J = 2.4 calorie 
or 1 calorie = 4 .186 J = 4.2 J (approx) 
Question 3. 
What do you understand by the term thermal capacity ? State its unit is SI system. 
Answer: 
Thermal capacity : “The amount of heat energy required to raise the temperature of a 
given mass of substance through 1°C (1k) is called thermal capacity”. 
Question 4. 
Define specific heat capacity and state its SI and CGS units. 
Answer: 
Specific heat capacity : “Is the amount of heat energy required to raise the temperature 
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of unit mass of a substance through 1°C or 1K is called specific heat capacity.” 
 
Question 5. 
Is the specific heat capacity of ice greater, equal to or less than water ? 
Answer: 
Specific heat capacity of ice is less than specific heat capacity of water. 
Question 6. 
Explain the following : 
(a) Water is used in hot water bottles for fomentation purposes. 
Answer: 
Water provides heat energy for longer time and does not cool quickly as specific heat 
capacity of water is large. 
(b) Water is used as a coolant in motor car radiators. 
Answer: 
When water is circulated in the pipes, it absorbs more amount of heat from 
surroundings (removes heat) without much rise in its temperature because of its high 
specific heat capacity. 
(c) A wise farmer always waters his fields in the evening, if there is a forecast for frost. 
Answer: 
To save the crops on such cold nights farmers fill their fields with water as water has 
high sp. heat capacity. So water does not allow the temp, in the surrounding area of 
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plants to fall upto 0°C. Other wise when temp, falls below 0°C water in the fine 
capillaries of plants will freeze, so the veins will burst due to increase in volume of water 
on freezing. 
(d) Wet soil does not get as hot as dry soil in the sun. 
Answer: 
Water has high sp. heat capacity as compared to soil (dry) and absorbs heat from 
surrounding for longer time and takes longer time to set as compared to dry soil. 
(e) Water is sprinkled on the roads in the evening during hot summer. 
Answer: 
Water has high sp. heat capacity and removes heat from the hot soil and decreases its 
temperature during hot summer evening. 
(f) Water is used for internal heating in cold countries. 
Answer: 
In cold countries water is used for internal heating as it can carry large amount of heat 
energy from the furnace to the rooms at a fairly moderate temperature. 
(g) Cold water is poured on the burns caused on the skin by some hot object. 
Answer: 
Water has high sp. heat capacity and can remove more heat from the bums caused on 
the skin by hot object and releives of the pain. 
(h) Water rubs are kept in warehouses storing fruits and vegetables in cold countries 
during winter. 
Answer: 
Water has high sp. heat capacity and water kept in tubs lose heat for a longer time and 
keep the surrounding hot for longer time and save the vegetables from busting due to 
increase in volume at low temp, of water present vegetables. 
Question 7. 
Explain how is land breeze caused ? 
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Calorimetry 
 
Exercise – 1 
Question 1. 
Define calorie. 
Answer: 
CALORIE : “Is the amount of heat energy required to raise the temperature of 1 g of 
water from 14.5 °C to 15.5°C”. 
Question 2. 
State the modern unit of heat energy. How is this unit related to calorie ? 
Answer: 
Modern unit of heat energy is joule 
Relation of joule with calorie : 
1 J = 2.4 calorie 
or 1 calorie = 4 .186 J = 4.2 J (approx) 
Question 3. 
What do you understand by the term thermal capacity ? State its unit is SI system. 
Answer: 
Thermal capacity : “The amount of heat energy required to raise the temperature of a 
given mass of substance through 1°C (1k) is called thermal capacity”. 
Question 4. 
Define specific heat capacity and state its SI and CGS units. 
Answer: 
Specific heat capacity : “Is the amount of heat energy required to raise the temperature 
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of unit mass of a substance through 1°C or 1K is called specific heat capacity.” 
 
Question 5. 
Is the specific heat capacity of ice greater, equal to or less than water ? 
Answer: 
Specific heat capacity of ice is less than specific heat capacity of water. 
Question 6. 
Explain the following : 
(a) Water is used in hot water bottles for fomentation purposes. 
Answer: 
Water provides heat energy for longer time and does not cool quickly as specific heat 
capacity of water is large. 
(b) Water is used as a coolant in motor car radiators. 
Answer: 
When water is circulated in the pipes, it absorbs more amount of heat from 
surroundings (removes heat) without much rise in its temperature because of its high 
specific heat capacity. 
(c) A wise farmer always waters his fields in the evening, if there is a forecast for frost. 
Answer: 
To save the crops on such cold nights farmers fill their fields with water as water has 
high sp. heat capacity. So water does not allow the temp, in the surrounding area of 
Downloaded from https://www.ncertbooksolutions.com/
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plants to fall upto 0°C. Other wise when temp, falls below 0°C water in the fine 
capillaries of plants will freeze, so the veins will burst due to increase in volume of water 
on freezing. 
(d) Wet soil does not get as hot as dry soil in the sun. 
Answer: 
Water has high sp. heat capacity as compared to soil (dry) and absorbs heat from 
surrounding for longer time and takes longer time to set as compared to dry soil. 
(e) Water is sprinkled on the roads in the evening during hot summer. 
Answer: 
Water has high sp. heat capacity and removes heat from the hot soil and decreases its 
temperature during hot summer evening. 
(f) Water is used for internal heating in cold countries. 
Answer: 
In cold countries water is used for internal heating as it can carry large amount of heat 
energy from the furnace to the rooms at a fairly moderate temperature. 
(g) Cold water is poured on the burns caused on the skin by some hot object. 
Answer: 
Water has high sp. heat capacity and can remove more heat from the bums caused on 
the skin by hot object and releives of the pain. 
(h) Water rubs are kept in warehouses storing fruits and vegetables in cold countries 
during winter. 
Answer: 
Water has high sp. heat capacity and water kept in tubs lose heat for a longer time and 
keep the surrounding hot for longer time and save the vegetables from busting due to 
increase in volume at low temp, of water present vegetables. 
Question 7. 
Explain how is land breeze caused ? 
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Answer: 
Land breeze : Blowing of cold air from land towards sea. During night temp, of land falls 
more rapidly as compared to water. Since water has high sp. heat capacity Pressure 
over sea water decrease and hence air blows from land (high pressure) towards sea 
(low pressure) 
Question 8. 
Explain the formation of sea breeze. 
Answer: 
Sea breeze : Blowing of cool air from sea towards land. During day time land gets 
heated up rapidly due to low sp. heat of land as compared to water. Pressure at land 
decreases. Hence air blows from sea (high pressure) towards land (low pressure). 
Question 9. 
Why is the weather in coastal regions moderate ? 
Answer: 
The climate near coastal regions moderate : The sp. heat capacity of water is very high 
or sp. heat capacity of land is much low as compared to water. As such land (or sand) 
gets cooled more rapidly as compared to water under similar conditions. Thus, a large 
difference in temperature is developed between the land and the sea, due to which cold 
air blows from land towards sea during night (i.e. land breeze) and during the day cold 
air blows from sea towards land (i.e. sand breeze). These make the climate near coastal 
region moderate. 
Multiple Choice Questions 
Tick ( ?) the most appropriate option. 
1. The specific heat capacity of a substance : 
(a) changes with the mass of given substance. 
(b) changes with the area or volume of substance. 
(c) changes with rise or fall in temperature. 
(d) is a constant quantity for a given substance. 
Answer: 
(d) is a constant quantity for a given substance. 
2. Land and sea breezes are formed in coastal regions because : 
(a) water has very high specific heat capacity than the land. 
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Calorimetry 
 
Exercise – 1 
Question 1. 
Define calorie. 
Answer: 
CALORIE : “Is the amount of heat energy required to raise the temperature of 1 g of 
water from 14.5 °C to 15.5°C”. 
Question 2. 
State the modern unit of heat energy. How is this unit related to calorie ? 
Answer: 
Modern unit of heat energy is joule 
Relation of joule with calorie : 
1 J = 2.4 calorie 
or 1 calorie = 4 .186 J = 4.2 J (approx) 
Question 3. 
What do you understand by the term thermal capacity ? State its unit is SI system. 
Answer: 
Thermal capacity : “The amount of heat energy required to raise the temperature of a 
given mass of substance through 1°C (1k) is called thermal capacity”. 
Question 4. 
Define specific heat capacity and state its SI and CGS units. 
Answer: 
Specific heat capacity : “Is the amount of heat energy required to raise the temperature 
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of unit mass of a substance through 1°C or 1K is called specific heat capacity.” 
 
Question 5. 
Is the specific heat capacity of ice greater, equal to or less than water ? 
Answer: 
Specific heat capacity of ice is less than specific heat capacity of water. 
Question 6. 
Explain the following : 
(a) Water is used in hot water bottles for fomentation purposes. 
Answer: 
Water provides heat energy for longer time and does not cool quickly as specific heat 
capacity of water is large. 
(b) Water is used as a coolant in motor car radiators. 
Answer: 
When water is circulated in the pipes, it absorbs more amount of heat from 
surroundings (removes heat) without much rise in its temperature because of its high 
specific heat capacity. 
(c) A wise farmer always waters his fields in the evening, if there is a forecast for frost. 
Answer: 
To save the crops on such cold nights farmers fill their fields with water as water has 
high sp. heat capacity. So water does not allow the temp, in the surrounding area of 
Downloaded from https://www.ncertbooksolutions.com/
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plants to fall upto 0°C. Other wise when temp, falls below 0°C water in the fine 
capillaries of plants will freeze, so the veins will burst due to increase in volume of water 
on freezing. 
(d) Wet soil does not get as hot as dry soil in the sun. 
Answer: 
Water has high sp. heat capacity as compared to soil (dry) and absorbs heat from 
surrounding for longer time and takes longer time to set as compared to dry soil. 
(e) Water is sprinkled on the roads in the evening during hot summer. 
Answer: 
Water has high sp. heat capacity and removes heat from the hot soil and decreases its 
temperature during hot summer evening. 
(f) Water is used for internal heating in cold countries. 
Answer: 
In cold countries water is used for internal heating as it can carry large amount of heat 
energy from the furnace to the rooms at a fairly moderate temperature. 
(g) Cold water is poured on the burns caused on the skin by some hot object. 
Answer: 
Water has high sp. heat capacity and can remove more heat from the bums caused on 
the skin by hot object and releives of the pain. 
(h) Water rubs are kept in warehouses storing fruits and vegetables in cold countries 
during winter. 
Answer: 
Water has high sp. heat capacity and water kept in tubs lose heat for a longer time and 
keep the surrounding hot for longer time and save the vegetables from busting due to 
increase in volume at low temp, of water present vegetables. 
Question 7. 
Explain how is land breeze caused ? 
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Answer: 
Land breeze : Blowing of cold air from land towards sea. During night temp, of land falls 
more rapidly as compared to water. Since water has high sp. heat capacity Pressure 
over sea water decrease and hence air blows from land (high pressure) towards sea 
(low pressure) 
Question 8. 
Explain the formation of sea breeze. 
Answer: 
Sea breeze : Blowing of cool air from sea towards land. During day time land gets 
heated up rapidly due to low sp. heat of land as compared to water. Pressure at land 
decreases. Hence air blows from sea (high pressure) towards land (low pressure). 
Question 9. 
Why is the weather in coastal regions moderate ? 
Answer: 
The climate near coastal regions moderate : The sp. heat capacity of water is very high 
or sp. heat capacity of land is much low as compared to water. As such land (or sand) 
gets cooled more rapidly as compared to water under similar conditions. Thus, a large 
difference in temperature is developed between the land and the sea, due to which cold 
air blows from land towards sea during night (i.e. land breeze) and during the day cold 
air blows from sea towards land (i.e. sand breeze). These make the climate near coastal 
region moderate. 
Multiple Choice Questions 
Tick ( ?) the most appropriate option. 
1. The specific heat capacity of a substance : 
(a) changes with the mass of given substance. 
(b) changes with the area or volume of substance. 
(c) changes with rise or fall in temperature. 
(d) is a constant quantity for a given substance. 
Answer: 
(d) is a constant quantity for a given substance. 
2. Land and sea breezes are formed in coastal regions because : 
(a) water has very high specific heat capacity than the land. 
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(b) land has very high specific heat capacity than the water. 
(c) sea water cools the cooler regions. . 
(d) all the above. 
Answer: 
(a) water has very high specific heat capacity than the land. 
3. The base of cooking pans is made thicker and heavy because: 
(a) it lowers the heat capacity of pan 
(b) it increases the heat capacity of pan 
(c) the food does not get charred and keeps hot for long time 
(d) both (a) and (c) 
Answer: 
(d) both (a) and (c) 
4. The S.I. unit of specific heat capacity is : 
(a) JKg
-1
 
(b) JK
-1
 
(c) JKg
-1 
K
-1
 
(d) kJkg
-1
 K
-1 
Answer: 
(b) Jk
-1
 
5. The specific heat capacity of water in S.I. system is : 
(a) 4.2 Jkg
-1
 K
-1
 
(b) 42 JKg
-1
 K
-1
 
(c) 4200 JKg
-1
 k
-1
 
(d) 420 JKg
-1
 K
-1 
Answer: 
(c) 4200 JKg
-1
 K
-1
 
6. S.I. unit of thermal capacity is : 
(a) Jkg
-1
 
(b) kJ Kg
-1
 
(c) Jkg
-1 
K
-1
 
(d) cal 
o
C
-1 
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