Cooling Drinks: Specific Latent Heat
Cooling Drinks
1. A value for the specific latent heat of fusion for water
Specific latent heat is the amount of heat energy that is needed to change the state of one kilogram of a specific substance, whether it’s boiling or melting, without increasing or decreasing the temperature of the substance.
Specific latent heat of fusion is the amount of heat energy that is needed to change a specific substance from solid to liquid. The specific latent heat of fusion for water is 334 KJ/ KG.
Each substance has its own specific latent heat of fusion. There is also specific latent heat of vaporisation. But this is the amount of energy needed to turn a liquid into a gas, without increasing or decreasing the temperature.
Below is a graph which is showing specific latent heat of fusion takes place. As the blue line ascends the temperature increases and as the line goes towards the right the time and energy given increases. As you can see when the ice is melting the temperature is staying constant but it is still giving energy. The energy given during this period is 334 kJ. [1]
[2]
Latent heat can be calculated using the following formula:
Where QL is the quantity of the heat in joules,
M is the mass in kg and l is the latent heat of the substance in J/kg
2. A value for the specific heat capacity of water
The specific heat capacity of a substance is the amount of heat energy that is needed to change the temperature of 1 kg of the substance by 1°C. Different substances have different specific heat capacities. The specific heat capacity of water is 4181 KJ. Water has quite a high specific heat capacity because water is useful for storing heat energy, and for transporting the heat energy for example in the central heating system heat is transferred via water. The standard way of finding out how much energy is needed to change the temperature of a substance is E= M*C*θ.
E is the energy transferred in joules, J
M is the mass
1. A value for the specific latent heat of fusion for water
Specific latent heat is the amount of heat energy that is needed to change the state of one kilogram of a specific substance, whether it’s boiling or melting, without increasing or decreasing the temperature of the substance.
Specific latent heat of fusion is the amount of heat energy that is needed to change a specific substance from solid to liquid. The specific latent heat of fusion for water is 334 KJ/ KG.
Each substance has its own specific latent heat of fusion. There is also specific latent heat of vaporisation. But this is the amount of energy needed to turn a liquid into a gas, without increasing or decreasing the temperature.
Below is a graph which is showing specific latent heat of fusion takes place. As the blue line ascends the temperature increases and as the line goes towards the right the time and energy given increases. As you can see when the ice is melting the temperature is staying constant but it is still giving energy. The energy given during this period is 334 kJ. [1]
[2]
Latent heat can be calculated using the following formula:
Where QL is the quantity of the heat in joules,
M is the mass in kg and l is the latent heat of the substance in J/kg
2. A value for the specific heat capacity of water
The specific heat capacity of a substance is the amount of heat energy that is needed to change the temperature of 1 kg of the substance by 1°C. Different substances have different specific heat capacities. The specific heat capacity of water is 4181 KJ. Water has quite a high specific heat capacity because water is useful for storing heat energy, and for transporting the heat energy for example in the central heating system heat is transferred via water. The standard way of finding out how much energy is needed to change the temperature of a substance is E= M*C*θ.
E is the energy transferred in joules, J
M is the mass