Specific Heat Capacities and Latent Heat: Master Thermodynamics Concepts

Question 1

Which of the following is the SI unit of specific heat capacity?

Accepted Answer

J/(kg K)

Answer

J/(kg °C)

Answer

J/(g K)

Answer

kJ/mol

Question 2

A 5 kg block of aluminum with a specific heat capacity of 0.9 kJ/(kg K) experiences a temperature increase of 20 K. How much energy is required for this temperature change?

Accepted Answer

7.2 kJ

Answer

18 kJ

Answer

36 kJ

Answer

45 kJ

Question 3

Which among the following substances possesses the highest specific heat capacity?

Accepted Answer

Water

Answer

Air

Answer

Iron

Answer

Ethanol

Question 4

Which of the terms describes the energy required to change the phase of a substance?

Accepted Answer

Latent heat

Answer

Specific heat

Answer

Calorific value

Answer

Enthalpy

Question 5

The latent heat of fusion for water is 334 kJ/kg. How much energy is required to melt 2 kg of ice at 0 °C?

Accepted Answer

668 kJ

Answer

267.2 kJ

Answer

1336 kJ

Answer

2672 kJ

Question 6

The phrase 'calorific value' commonly refers to:

Accepted Answer

Enthalpy of combustion

Answer

Specific heat capacity

Answer

Latent heat

Answer

Heat capacity ratio

Question 7

What is the SI unit of specific heat capacity?

Accepted Answer

J/kg°C

Answer

J/g°C

Answer

J/kg

Answer

J/g

Question 8

Which of the following substances has the highest specific heat capacity?

Accepted Answer

Water

Answer

Copper

Answer

Iron

Answer

Aluminum

Question 9

What is the latent heat of fusion?

Accepted Answer

The amount of heat required to change a substance from a liquid to a solid

Answer

The amount of heat required to change a substance from a liquid to a gas

Answer

The amount of heat required to change a substance from a solid to a liquid

Answer

The amount of heat required to change a substance from a gas to a solid

Question 10

Which of the following factors does NOT affect the specific heat capacity of a substance?

Accepted Answer

Mass

Answer

Temperature

Answer

Pressure

Answer

Molecular structure

Question 11

The specific heat capacity of a substance is a measure of its ability to:

Accepted Answer

Absorb heat

Answer

Conduct heat

Answer

Change temperature rapidly

Answer

Maintain a constant temperature

Question 12

Which substance has the highest specific heat capacity?

Accepted Answer

Water

Answer

Air

Answer

Iron

Answer

Wood

Question 13

Latent heat is the heat absorbed or released during:

Accepted Answer

A change in phase

Answer

A change in temperature

Answer

A chemical reaction

Answer

A mechanical process

Question 14

Which of the following is the latent heat of fusion?

Accepted Answer

Heat absorbed when a substance changes from a solid to a liquid

Answer

Heat released when a substance changes from a liquid to a solid

Answer

Heat absorbed when a substance changes from a liquid to a gas

Answer

Heat released when a substance changes from a gas to a liquid

Question 15

The specific heat capacity of water is significant because:

Accepted Answer

It helps calculate the heat needed to change water's temperature

Answer

It affects the water's thermal conductivity

Answer

It indicates the maximum temperature water can reach

Answer

It is used to determine the rate of heat absorption or release

Question 16

The latent heat of vaporisation of a substance is:

Accepted Answer

A constant value for a given substance

Answer

Equal to the specific heat capacity of the substance

Answer

Dependent on the temperature at which the substance boils

Answer

Always zero for all substances

Question 17

The specific heat capacity of air compared to that of water is:

Accepted Answer

Much lower

Answer

Much higher

Answer

Slightly higher

Answer

Slightly lower

Question 18

The International System of Units (SI) unit of specific heat capacity is:

Accepted Answer

Joules per kilogram kelvin

Answer

Calories per gram degree Celsius

Answer

British thermal units per pound degree Fahrenheit

Answer

Kilocalories per mole kelvin

Question 19

A substance undergoes a phase change when:

Accepted Answer

Its energy content changes

Answer

Its temperature changes

Answer

Its pressure changes

Answer

Its volume changes

Question 20

The latent heat of fusion represents the amount of heat required to:

Accepted Answer

Convert a solid to a liquid at its melting point

Answer

Increase the temperature of a solid by 1°C

Answer

Convert a liquid to a gas at its boiling point

Answer

Decrease the temperature of a gas by 1°C

Question 21

Among the following substances, which has the highest specific heat capacity?

Accepted Answer

Water

Answer

Iron

Answer

Copper

Answer

Aluminium

Question 22

The primary purpose of a calorimeter is to:

Accepted Answer

Measure the specific heat capacity of a substance

Answer

Measure the heat capacity of a substance

Answer

Measure the latent heat of fusion of a substance

Answer

Measure the latent heat of vaporisation of a substance

Question 23

The latent heat of vaporisation represents the amount of heat required to:

Accepted Answer

Convert a liquid to a gas at its boiling point

Answer

Convert a solid to a liquid at its melting point

Answer

Increase the temperature of a liquid by 1°C

Answer

Decrease the temperature of a gas by 1°C

Question 24

The specific heat capacity of a substance can be used for:

Accepted Answer

Calculating the heat required to change its temperature

Answer

Calculating the energy released or absorbed during a phase change

Answer

Determining the thermal conductivity of the substance

Answer

Predicting the melting point of the substance

Question 25

A substance with a large latent heat of fusion:

Accepted Answer

Requires more heat to melt

Answer

Reaches a higher temperature when melted

Answer

Solidifies more quickly

Answer

Evaporates more easily

Question 26

Which of the following is NOT a common application of specific heat capacities in practical settings?

Accepted Answer

Estimating cooking times for different foods

Answer

Designing cooling systems for electronic devices

Answer

Predicting the thermal behavior of construction materials

Answer

Calculating energy requirements for industrial processes

Question 27

Define specific heat capacity, denoted as 'c'.

Accepted Answer

The amount of heat energy required to raise the temperature of 1 kg of a substance by 1 K

Answer

The amount of heat energy required to raise the temperature of 1 g of a substance by 1 °C

Answer

The amount of heat energy required to change the phase of 1 g of a substance

Question 28

Which of the following substances has the highest specific heat capacity?

Accepted Answer

Water

Answer

Aluminum

Answer

Wood

Answer

Iron

Question 29

Explain the meaning of 'latent heat'.

Accepted Answer

The heat energy required for a substance to undergo a phase change at constant temperature

Answer

The heat energy released when a substance cools down

Answer

The heat energy required to raise the temperature of a substance by 1 K

Question 30

State the SI unit of specific heat capacity.

Accepted Answer

J/(kg·K)

Answer

cal/(g·°C)

Answer

J/(g·°C)

Answer

kcal/(kg·K)

Question 31

A substance with a specific heat capacity of 500 J/(kg·K) absorbs 25 kJ of heat during a phase change from solid to liquid. Determine the mass of the substance.

Accepted Answer

50 kg

Answer

500 kg

Answer

100 kg

Answer

25 kg

Question 32

Which factor has the greatest influence on the specific heat capacity of a substance?

Accepted Answer

Chemical composition

Answer

Volume

Answer

Temperature

Answer

Pressure

Question 33

The amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius is known as its:

Accepted Answer

Specific heat capacity

Answer

Enthalpy

Answer

Latent heat of fusion

Answer

Latent heat of vaporization

Question 34

The latent heat of fusion of a substance is:

Accepted Answer

The amount of heat required to change 1 gram of a solid to a liquid at its melting point

Answer

The amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius

Answer

The amount of heat required to change 1 gram of a liquid to a gas at its boiling point

Question 35

Which of the following has the highest latent heat of vaporization?

Accepted Answer

Water

Answer

Nitrogen

Answer

Ethanol

Answer

Mercury

Question 36

Which statement best defines latent heat?

Accepted Answer

Latent heat is the energy absorbed or released during a phase change, without a change in temperature.

Answer

Latent heat is the energy transferred due to a difference in temperature.

Answer

Latent heat is the energy required to raise the temperature of a substance.

Answer

Latent heat is the energy stored in the chemical bonds of a substance.

Question 37

Calculate the total energy absorbed by 1 kg of ice at 0°C as it melts completely. Assume the latent heat of fusion for ice is 334 kJ/kg.

Accepted Answer

334 kJ

Answer

334 J

Answer

4.18 kJ

Answer

100 kJ

Question 38

Which of the following materials is known to have the highest specific heat capacity?

Accepted Answer

Water

Answer

Steel

Answer

Copper

Answer

Aluminum

Question 39

Why is water commonly used as a coolant in car radiators?

Accepted Answer

Water has a high specific heat capacity, allowing it to absorb large amounts of heat without significant temperature changes.

Answer

Water is readily available and inexpensive.

Answer

Water has a low boiling point, making it evaporate easily.

Answer

Water is a good conductor of electricity.

Question 40

Calculate the heat energy required to convert 100 g of water at 100°C to steam at 100°C. The latent heat of vaporization for water is 2260 kJ/kg.

Accepted Answer

226 kJ

Answer

41.8 kJ

Answer

100 kJ

Answer

226 J

Question 41

How does sweating contribute to cooling the body?

Accepted Answer

Evaporation of sweat absorbs heat from the body's surface, resulting in a cooling effect.

Answer

Sweat creates a thin layer of moisture on the skin, which acts as insulation.

Answer

Sweat helps regulate body temperature by increasing blood flow.

Answer

Sweat removes dirt and impurities from the skin.

Question 42

A 2 kg block of copper is heated from 25°C to 75°C. What is the change in temperature of the copper block in Kelvin?

Accepted Answer

50 K

Answer

75 K

Answer

25 K

Answer

100 K