An Investigation of Heat Transfer Through the Method of Mixtures

Understanding how heat is transferred between objects is essential in explaining many real-world physical and chemical processes. One important property related to heat transfer is specific heat capacity, which describes how much heat a substance needs to change its temperature. In this activity, students will explore the concept of calorimetry using the method of mixtures to investigate heat exchange and identify an unknown metal. This hands-on experiment will allow students to apply theoretical concepts to practical measurements and deepen their understanding of thermal equilibrium and energy conservation.

The task is to determine the specific heat capacity of an unknown metal using a calorimeter and the method of mixtures. Students will measure the heat absorbed and released by the metal and water, compute the metal’s specific heat, compare the experimental value with theoretical values, and identify the unknown metal. The final output includes completed data tables, detailed computations, identification of the metal, percentage error analysis, and a written conclusion.

MATERIALS:

1. Gently pour 250 mL of tap water into a 400 mL beaker. Place the beaker on a hot plate and heat the water until it reaches a boil. While the water is heating, proceed to the next step.
2. Grab the metal sample. Measure and record its mass using a triple beam balance.
3. Using crucible tongs or tweezers, carefully transfer the metal into the 400 mL beaker containing boiling water at approximately 100 °C. Let the metal remain in the boiling water for 10 minutes. While the metal is heating, proceed to Steps 4 and 5.
4. Obtain 100 mL of tap water using a 250 mL beaker and transfer it into a Styrofoam cup. Record the mass of the water, noting that for water, 1 mL is equivalent to 1 g.
5. Place the Styrofoam cup containing the water inside a second empty Styrofoam cup and cover it. Insert a thermometer and stirring rod through the opening in the cover. Once the thermometer reading stabilizes, record the temperature. This value represents the initial temperature of the water.
6. After the metal has been heated for ten minutes, measure and record the temperature of the boiling water using a thermometer. This temperature represents the initial temperature of the metal sample.
7. Using crucible tongs or tweezers, quickly remove the metal sample from the boiling water and transfer it into the calorimeter. Perform this step promptly to minimize heat loss. Cover the calorimeter and stir the mixture with a stirring rod for at least ten seconds. Once the thermometer reading stabilizes, record the temperature. This value represents the final equilibrium temperature of the metal and water.
8. Record all the data collected in Table 1.
9. Repeat the same procedure for Trial 2.
10. Identify the metal used in the experiment by comparing the calculated specific heat with standard values for different metals. Compute the percentage error and record the results in Table 2.
    
     

    DATA:

    	TRIAL 1	TRIAL 2	AVERAGE
    Mass of Metal (kg)
    Mass of Water in the Calorimeter (kg)
    Initial Temperature of Water in the Calorimeter (°F)
    Initial Temperature of Metal (°F)
    Final Temperature of Water in the Calorimeter (°F)
    Final Temperature of Metal (°F)
    ∆T of Water (°F)
    ∆T of Metal (°F)
    Specific Heat of Metal (J/kg°C)

    TABLE 1. DATA

     

    KIND OF METAL	SPECIFIC HEAT (THEORETICAL VALUE)	SPECIFIC HEAT (EXPERIMENTAL VALUE)	PERCENTAGE ERROR

    TABLE 2. PERCENTAGE ERROR

    COMPUTATIONS/SOLUTIONS:
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
     

CONCLUSION: