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Specific Heat Lab

Specific Heat Results

q is the symbol for heat energy
a negative value means that heat is being released by the substance. A positive value means heat is being absorbed by the system.
J

c is the symbol for specific heat
specific heat is how fast or slow a substance can absorb or release heat energy
J/goC

To determine the heat energy released or absorbed by a substance we use a calorimeter.
Since we know the specific heat of water: 4.184 J/goC we can set up for q of water
We obtained the mass of water , the initial temperature of water and the final temperture of water. So we can calculate the heat energy absorbed by the water in the calorimeter.

Example calc: qwater = 220g(4.184J/goC)(27.4 - 24.8oC)

To obtain the heat energy of lead, we know that the 2 systems were in equilibrium.
-qlead = qwater

Example -q = 2761Joules

The initial temperature of lead was 100.0oC since we place the lead sinker in a pot of boiling water for 5 minutes to establish equilibrium between the lead and water.
We know the weight of lead the initial and final temperatures (this will be a negative value since lead released heat, 24.8 - 100.0) and we can find q for lead
q = mc(Final Temp - Initial Temp)

What we don't know is c, the specific heat. We determine specific heat by calculation.
c = q/m(Tf - Ti)
c = -2761J/30g(-75.2oC) =1.22

Errors

If we were to do this lab again....... I would make sure the initial temperature of the water that went into the calorimeter was lower. It was hard for us to observe any significant temperature change once we placed the lead sinker in the calorimeter.

Can you think of anything else you would do differently?

Do you think any heat was lost to the environment outside of the calorimeter????

Conclusion

The objective of this lab was to measure the specific heat of lead using a styrofoam calorimeter.
How did we do this? By making a simple styrofoam cup calorimeter we were able to measure the heat absorbed by water and calculate the heat released by the lead.
It was determined from this experiment that lead has a specific heat capacity of ?????. Will lead absorb heat quickly based on this value? Will lead release heat quickly based on this value????
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