Heating Processes COPY Flashcards
What is the specific heat capacity of a substance
The amount of energy required to change the temperature of one kilogram of the substance by one degree Celsius
What is the relationship between energy, mass, specific heat capacity and temperature change
Energy = mass x specific heat capacity x temperature change E = m x c x θ
What is the specific latent heat of vaporisation of a substance
The amount of energy required to change the state of one kilogram of the substance from a liquid to a vapour with no change in temperature
What is the relationship between energy , mass and specific latent heat of vaporisation
Energy = mass x specific latent heat of vaporisation E = m x Lv
What is the specific latent heat of fusion of a substance
The amount of energy required to change the state of one kilogram of the substance from a solid to a liquid with no change in temperature
What is the relationship between energy , mass and specific latent heat of fusion
Energy = mass x specific latent heat of fusion E = m x Lf
What are the melting point of a solid and the boiling point of a liquid affected by
Impurities
What happens in a cooling curve
-Temperature remains constant because energy is released during the formation of bonds -The release of energy compensates the energy lost to the surroundings and keeps the temperature constant
What happens in a heating curve
-Particles of ice gain energy from the surroundings. The average kinetic energy of the particles increases and so does the temperature. -Energy from the surroundings is used to break the bonds between the ice particles instead of increasing the kinetic energy of the particles. Average kinetic energy of particles remain constant, so temperature remains constant. -When the solid has transformed into a liquid, energy from the surroundings goes into raising the average kinetic energy and the temperature increases
What two processes may energy be transferred by
Conduction and convection
Convection
Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy
Factors affection the rate of evaporation
-Increasing the surface area of a liquid -Increasing the temperature of the liquid -Creating a draught of air across the liquids surface
How does an increase in the temperature difference between and object and its surroundings affect the rate at which energy is transferred by heating
The BIGGER the temperature difference between an object and its surroundings, the FASTER the rate at which energy is transferred by heating
