Heat Capacity

What three factors must be considered when determining the quantity of heat required to raise temperature?

1. Mass of the substance 2. Desired change in temperature (ΔT) 3. Type of substance (heat capacity)

What is the definition of specific heat capacity?

The amount of heat needed to raise the temperature of one gram of a substance by one degree.

If you want to raise the temperature of 1g of silver by 10 °C, how much heat is required?

It would take 2.4 J because 0.24 J/g°C x 10 °C = 2.4 J.

What is the formula for calculating the quantity of heat (q)?

q = mcΔT, where m is mass, c is specific heat capacity, and ΔT is the change in temperature.

What is the specific heat capacity of aluminum?

0.90 J/g°C.

What units measure heat in this lecture?

Joules (J), Kilojoules (kJ), calories (cal), and kilocalories (kcal).

How do you calculate the specific heat capacity if you know the amount of heat added, mass, and temperature change?

c = q / (m x ΔT).

What is heat transfer?

The process of thermal energy moving from one object or substance to another due to a temperature difference.

What are the three modes of heat transfer?

Conduction, convection, and radiation.

How does conduction occur?

Through direct contact between materials, transferring kinetic energy from faster (hotter) particles to slower (cooler) particles.

What is convection?

The transfer of heat through fluid (liquid or gas) movement, often involving the circulation of warmer, less dense regions rising and cooler, denser regions sinking.

What is radiation in terms of heat transfer?

The transfer of heat energy through electromagnetic waves, which can occur in a vacuum.

What happens to the specific heat capacity of a substance as its temperature increases?

Specific heat capacity may change with temperature, usually increasing as temperature rises.

What is the importance of knowing the specific heat capacity of substances?

It helps predict how much energy is needed for heating or cooling processes in physical and chemical reactions.

What is a calorimeter?

An instrument used to measure the amount of heat involved in a chemical reaction or other process.

What does thermal equilibrium refer to?

A state when two objects in contact with each other reach the same temperature and no heat flows between them.

Why is water known to have a high specific heat capacity?

Water requires a significant amount of heat to change its temperature due to hydrogen bonding, making it effective for regulating temperatures in natural systems.

What factors influence heat transfer in materials?

The temperature difference, the material's thermal conductivity, and the surface area in contact.

What is thermal conductivity?

The property of a material to conduct heat, measured in watts per meter per degree Celsius (W/m·°C).

Which material has the highest thermal conductivity?

Silver is known to have the highest thermal conductivity among all materials.

What is latent heat?

The amount of heat absorbed or released by a substance during a phase change without changing its temperature.

What is the difference between endothermic and exothermic processes?

Endothermic processes absorb heat, while exothermic processes release heat.

What is the role of specific heat capacity in climate science?

It helps understand how different materials (like water vs. land) heat and cool at different rates, influencing weather patterns.

How does the presence of impurities affect the specific heat capacity of a substance?

Impurities generally lower the specific heat capacity of a pure substance.

What is the significance of heat in chemical reactions?

Heat changes can indicate whether a reaction is exothermic or endothermic, affecting reaction rates and equilibrium.

What is thermal resistance?

The measure of a material's ability to resist heat flow, often used in building and insulation materials.

How can the calorimetry technique aid in understanding heat transfer?

Calorimetry allows for the precise measurement of heat transfer during chemical reactions or physical changes, providing insights into energy dynamics.

What is thermal energy?

Thermal energy is the energy that comes from the temperature of matter; it is the total kinetic energy of particles in a substance.

What does the term 'heat capacity' refer to?

Heat capacity is the amount of heat energy required to raise the temperature of a substance by one degree Celsius.

What are the units for measuring specific heat capacity?

The specific heat capacity is measured in joules per gram per degree Celsius (J/g·°C).

What role does specific heat capacity play in cooking?

Specific heat capacity influences cooking times and temperatures for different materials, affecting how quickly food heats or cooks.

What is a practical application of the calorimetry technique?

Calorimetry can be used to determine the heat of combustion of fuels, providing insights into energy content.

How does specific heat capacity affect climate and weather patterns?

Materials with high specific heat capacity, like water, moderate temperature changes, influencing climate stability and regional weather.

What happens to the heat during a phase change?

During a phase change, heat is absorbed or released without changing the temperature of the substance.

What is an example of an endothermic reaction?

Photosynthesis is an example of an endothermic reaction, as it absorbs heat energy to convert CO2 and water into glucose.

What is an example of an exothermic reaction?

The combustion of fuels, such as burning wood or gasoline, is an example of an exothermic reaction, as it releases heat.

How do you calculate the amount of heat lost or gained by a substance?

Using the formula q = mcΔT, where q is the heat gained or lost, m is mass, c is specific heat capacity, and ΔT is the temperature change.

Heat is..

Thermal Energy

Temperature is..

is average kinetic