Therefore, the heat released when 2g of water is colled from 70°C to 10°C is 504J. Negative sign in the answer indicates that heat is released by water.
Answer:
The heat released when 2g of water is colled from 70°C to 10°C is 504J.
Learn More:
First Law of Thermodynamics: Heat given to a thermodynamic system (dQ) is partly utilized in doing work (dW) against the surrounding and the remaining part is utilised in increasing the internal energy (dU) of the system.
It is based on the law of conservation of energy.
Second Law of Thermodynamics: It is impossible to transfer heat from a body of lower temperature to a body of higher temperature without the use.
This implies that heat always flow from a body of higher temperature to a body of lower temperature.
Third Law of Thermodynamics: The entropy of a pure and perfectly crystalline substance at absolute zero is zero.
The entropy is the measure of the disorderliness of a system.
Answers & Comments
Answer:
The amount of heat energy can be calculated using the equation:
Q = m * c * ΔT
Where:
m = mass of water = 2 g
c = specific heat capacity of water = 4.2 J/g°C
ΔT = change in temperature = 70°C - 10°C = 60°C
So, Q = 2 g * 4.2 J/g°C * 60°C = 504 J
Therefore, the amount of heat energy when 2 grams of water is cooled from 70°C to 10°C is 504 J.
Verified answer
Solution:
Given that:
[tex]\tt\longrightarrow Mass\:Of\:Water=2\:g[/tex]
[tex]\tt\longrightarrow Initial\:Temperature=70^{\circ}C[/tex]
[tex]\tt\longrightarrow Final\:Temperature=10^{\circ}C[/tex]
[tex]\tt\longrightarrow Specific\:Heat\:Capacity=4.2\:J\:g^{-1}{\:}^{\circ}C^{-1}[/tex]
We know that:
[tex]\bigstar\:\:\underline{\boxed{\tt Q=mc\theta}}[/tex]
Where:
[tex]\tt\longrightarrow Q=Heat\:gained/lost[/tex]
[tex]\tt\longrightarrow m=Mass[/tex]
[tex]\tt\longrightarrow c=Specific\:Heat\:Capacity[/tex]
[tex]\tt\longrightarrow \theta=Change\:in\:Temperature=T_{f}-T_{i}[/tex]
Therefore:
[tex]\tt\longrightarrow Q=mc\theta[/tex]
[tex]\tt\longrightarrow Q=(2)\cdot (4.2)\cdot(10-70)\:J[/tex]
[tex]\tt\longrightarrow Q=-504\:J[/tex]
Therefore, the heat released when 2g of water is colled from 70°C to 10°C is 504J. Negative sign in the answer indicates that heat is released by water.
Answer:
Learn More:
First Law of Thermodynamics: Heat given to a thermodynamic system (dQ) is partly utilized in doing work (dW) against the surrounding and the remaining part is utilised in increasing the internal energy (dU) of the system.
It is based on the law of conservation of energy.
Second Law of Thermodynamics: It is impossible to transfer heat from a body of lower temperature to a body of higher temperature without the use.
This implies that heat always flow from a body of higher temperature to a body of lower temperature.
Third Law of Thermodynamics: The entropy of a pure and perfectly crystalline substance at absolute zero is zero.
The entropy is the measure of the disorderliness of a system.