how is temperature change for a pathway step used to determine the value for the amount of heat transferred?
How is temperature change for a pathway step used to determine the value for the amount of heat transferred?
Answer: To determine the amount of heat transferred during a temperature change, we use the concept of specific heat capacity. This involves a simple equation that relates heat transfer to temperature change, mass, and the specific heat capacity of the substance.
The Equation
The equation used is:
Where:
- q is the heat transferred.
- m is the mass of the substance.
- c is the specific heat capacity, which is the amount of heat needed to raise the temperature of 1 gram of the substance by 1 degree Celsius.
- \Delta T is the change in temperature, calculated as the final temperature minus the initial temperature.
Step-by-Step Explanation
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Measure the Mass (m): Determine the mass of the substance you are studying. It should be in grams.
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Determine the Temperature Change (\Delta T): Subtract the initial temperature from the final temperature to find \Delta T.
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Use the Specific Heat Capacity (c): Find the specific heat capacity of the substance. This value is unique to each material and is usually provided in joules per gram per degree Celsius (J/g°C).
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Calculate the Heat Transfer (q): Plug the values into the formula q = mc\Delta T to find the heat transferred. The result will give you the amount of heat in joules.
Example
Let’s say we have 100 grams of water (with a specific heat capacity of 4.18 J/g°C), and its temperature changes from 20°C to 30°C.
- Mass m: 100 grams
- Temperature change \Delta T: 30°C - 20°C = 10°C
- Specific heat capacity c: 4.18 J/g°C
Substitute these values into the formula:
So, 4180 joules of heat is transferred.
Summary: To find the amount of heat transferred due to a temperature change, use the formula q = mc\Delta T. Measure the mass, determine the temperature change, and use the specific heat capacity for the calculation. This method gives you the amount of heat transferred in a given pathway step.