Thermal physics; specific heat capacity

In summary, the copper in the flame of a Bunsen burner raised the water's temperature by 3.78*10^4 Joules.
  • #1
saccapella
10
0

Homework Statement


In an experiment to measure the temperature of the flame of a Bunsen burner, a lump of copper of mass 0.12 kg is heated in the flame for several minutes. The copper is then transferred quickly to a beaker, of negligible heat capacity, containing 0.45 kg of water, and the temperature rise of the water measured.

a)Temperature of water rises from 15 to 35degrees. Calculate thermal energy gained by the water.
b)Calculate the temperature reached by the copper in the flame. Assume no heat is lost when copper is transferred.

Specific heat capacity of water = 4200jkg^-1K^-1
Specific heat capacity of copper = 390jkg^-1K^-1


Homework Equations



Q=mc(final temperature - initial temperature)

The Attempt at a Solution



a)Q=0.45*4200*20
Q=3.78*10^4J

b)none... this is where i got stuck :/ help please!
 
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  • #2
The heat that ended up raising the water's temperature came from somewhere. Where did it come from?
 
  • #3
gneill said:
The heat that ended up raising the water's temperature came from somewhere. Where did it come from?

The copper?
 
  • #4
saccapella said:
The copper?

Yes, the copper. How much heat did it give up to the water? What is the copper's final temperature?
 
  • #5
gneill said:
Yes, the copper. How much heat did it give up to the water? What is the copper's final temperature?

3.78*10^4J...

3.78*10^4J=0.12*390*change in temperature

so change in temperature = 808?

This is where I get stuck on...I don't know how to find the final temperature
 
  • #6
What is the final temperature of the copper as it sits in the water bath?
 
  • #7
gneill said:
What is the final temperature of the copper as it sits in the water bath?

35 degrees

Edit: Misread what you said lol, final temperature of the copper as it sits in the water bath? 843?
 
  • #8
Right. The copper and water reach temperature equilibrium. So Tf = 35, and you're looking for Ti for the copper. If Q is your heat value, mc the copper mass and cc the copper specific heat capacity, then

Q = mc*cc*ΔT

where ΔT is the difference between the initial and final temperatures (I've assumed all positive values for simplicity).
 
  • #9
saccapella said:
35 degrees

Edit: Misread what you said lol, final temperature of the copper as it sits in the water bath? 843?

No, no, you were correct the first time (before edit). The water and copper reach an equilibrium temperature of 35 degrees. 843 degrees, then, is the initial temperature of the copper when it is first placed into the water.
 
  • #10
Ohh, I see what you did. Thanks!
 
  • #11
gold penny lab, i remmber doing this it was fun. sorry we didint have these questions, maybe you should search for gold penny lab.
 

FAQ: Thermal physics; specific heat capacity

1. What is specific heat capacity?

Specific heat capacity is the amount of heat energy required to raise the temperature of one unit of mass of a substance by one degree Celsius.

2. How is specific heat capacity measured?

Specific heat capacity is measured using a calorimeter, which is a device that measures the heat exchange between a substance and its surroundings.

3. Why is specific heat capacity important?

Specific heat capacity is important because it helps us understand how different substances respond to changes in temperature and how much heat energy is required to cause a temperature change.

4. What factors affect the specific heat capacity of a substance?

The specific heat capacity of a substance is affected by its mass, composition, and molecular structure.

5. How does specific heat capacity differ from heat capacity?

Specific heat capacity is the amount of heat energy required to raise the temperature of one unit of mass of a substance by one degree Celsius, while heat capacity is the amount of heat energy required to raise the temperature of an object by one degree Celsius.

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