Test: Calorimetry - Class 10 MCQ

The principle of calorimetry states that in an insulated system, the heat energy lost by a hot body is equal to the heat energy gained by a cold body. This principle is fundamental for measuring heat exchanges.

Melting is the process of changing from solid to liquid upon heating at a constant temperature, known as the melting point.

When the pressure on the surface of a liquid increases, its boiling point also increases. This is why pressure cookers can cook food faster; they raise the boiling point of water.

The specific heat capacity c of a substance is calculated using the formula c = Q / (m × ΔT), where Q is the heat energy supplied, m is the mass, and ΔT is the change in temperature.

The presence of impurities typically lowers the melting point of a substance. This is why salt is often added to ice in freezing mixtures; it helps to lower the melting point further.

The change of phase from solid to liquid occurs at a constant temperature known as the melting point. This phase change requires heat energy to break the bonds holding the solid structure together.

Specific heat capacity is defined as the heat capacity per unit mass of a substance, indicating how much heat energy is needed to raise the temperature of a unit mass by 1°C (or 1 K).

The high specific heat capacity of water makes it effective in cooking food, as it can absorb a lot of heat without a significant rise in temperature, allowing for even cooking.

The SI unit of heat is the joule (J). It is the standard unit used in the International System of Units to measure energy, including heat energy.

Copper is commonly used to construct calorimeters because it is an excellent conductor of heat, allowing for quick temperature equilibration with the contents of the calorimeter.

The heat capacity of a body is defined as the amount of heat required to raise its temperature by 1°C, which is a crucial measure in thermal energy calculations.

Heat capacity is defined as the amount of heat energy required to change the temperature of a body by 1°C (or 1 K). It is an essential concept in understanding how materials respond to heat.

The heating curve for naphthalene illustrates that during phase changes, such as melting and freezing, the temperature remains constant, while heat energy is absorbed or released.

The addition of impurities typically raises the boiling point of a liquid. For instance, adding salt to water raises its boiling point, which is useful in cooking as it allows food to cook at higher temperatures.

The specific latent heat of ice contributes to gradual melting, allowing snow on mountains to melt slowly, which helps regulate temperature and water supply in ecosystems.

The electrical method is particularly effective for measuring the specific heat capacity of good conductors like copper and aluminum, as they heat uniformly under controlled conditions.

During the melting of ice, the temperature remains constant at 0°C until all the ice has melted. The heat supplied is used for the phase change rather than raising the temperature.

Latent heat refers to the heat energy exchanged during phase changes (such as melting or boiling) without a change in temperature. It is often described as "hidden" heat.

The specific latent heat of fusion is the heat energy required to convert a unit mass of a substance from solid to liquid without changing its temperature. This is crucial in understanding melting processes.

The volume of the body does not affect the quantity of heat required to raise its temperature. The relevant factors are the mass of the body, the nature of the material, and the desired rise in temperature.