Calorimetry problem and temperature

In summary, the student attempted to identify a metal by measuring its specific heat capacity. 100g of the metal was heated to 75°C and then transferred to a 70g copper calorimeter containing 200g of water at 20°C. The temperature of the final mixture was 25°C.
  • #1
crosbykins
53
0

Homework Statement


A student attempts to identify a metal by measuring its specific heat capacity. 100g of the metal is heated to 75°C and then transferred to a 70g copper calorimeter containing 200g of water at 20°C. The temperature of the final mixture is 25°C.


Homework Equations



heat lost by sample = heat gained by water

The Attempt at a Solution


Given metal: Given water:
m = .1kg m = .2kg
c = ? c = 4.2e3 J/kg°C
t1 = 75°C t1 = 20°C
t2 = 25°C t2 = 25°C
c = - [.2kg * 4.2e3 J/kg°C]/ *25°C - 20°C/
.1kg 25°C - 75°C
= 840 J/kg°C
ok well..this is wrong...does the fact that the calorimeter is 70g copper affect the answer
 
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  • #2
Do you how much heat is needed to change the temperature of 1 kg of water by 1 degree Celsius. It is 4186 Joule. So How much heat is needed to change the temperature of 200 g of water by 1 degree Celsius ? It is 5 time less heat than 1 Kg of water. But you have changed the temperature of water by 5 degree Celsius. So total heat needed to change the temperature of 200 g of water by 5 degree Celsius is:

(4186 * 5)/5

= 4186 Joule.

Now copper also needed some heat to raise its temperature by 5 degree Celsius.

We need 387 Joule of heat to raise the temperature of 1 kg of copper by 1 degree Celsius.

So to raise the temperature of 70 g copper by 5 degree Celsius is ...?

Now add both the heat and find what is the total heat lost by the metal and due to this lost how much is the change in the temperature. From there you can find its specific heat.
 
  • #3
It may be nearly equal to 864.29 J/kg per degree Celsius. Is I'm right? I'm not very good with Physics so I apologize if I've mislead you on any step.
 
  • #4
snshusat161 said:
Do you how much heat is needed to change the temperature of 1 kg of water by 1 degree Celsius. It is 4186 Joule. So How much heat is needed to change the temperature of 200 g of water by 1 degree Celsius ? It is 5 time less heat than 1 Kg of water. But you have changed the temperature of water by 5 degree Celsius. So total heat needed to change the temperature of 200 g of water by 5 degree Celsius is:

(4186 * 5)/5

= 4186 Joule.

Now copper also needed some heat to raise its temperature by 5 degree Celsius.

We need 387 Joule of heat to raise the temperature of 1 kg of copper by 1 degree Celsius.

So to raise the temperature of 70 g copper by 5 degree Celsius is ...?

Now add both the heat and find what is the total heat lost by the metal and due to this lost how much is the change in the temperature. From there you can find its specific heat.
-so copper's heat gained is (387J *5)/14 =138J...so the heat gained by both is 4324J...so that's the heat lost by the sample, so the sample's specific heat capacity is...864J/Kg*C...but that's no the right answer..b/c the choices i have to choose from for the answer are 4200J/Kg*K, 900J/Kg * K, 440J/kg *, 390, 370, 130...
 
  • #5
Tell the correct answer. Is it 900 J/ kg *K. Is it Aluminum.
 

1. What is calorimetry and why is it important?

Calorimetry is the scientific measurement of the amount of heat released or absorbed during a chemical or physical process. It is important because it allows scientists to study the energy changes that occur in reactions and understand the thermodynamics of a system.

2. How is temperature related to calorimetry?

Temperature is a key factor in calorimetry because it is used to measure the amount of heat exchanged in a system. In calorimetry experiments, temperature changes are used to calculate the heat absorbed or released by a substance.

3. What is a calorimeter and how is it used in temperature measurement?

A calorimeter is a device used to measure heat changes in a system. It typically consists of a container, an insulating material, and a thermometer. The substance being studied is placed inside the container, and the temperature change is measured using the thermometer. This allows for accurate measurement of the heat exchange in a system.

4. How is specific heat capacity used in calorimetry problems?

Specific heat capacity is the amount of heat required to raise the temperature of a substance by 1 degree Celsius. In calorimetry problems, it is used to calculate the amount of heat absorbed or released by a substance based on its mass, temperature change, and specific heat capacity.

5. What are some common sources of error in calorimetry experiments?

Some common sources of error in calorimetry experiments include heat loss to the surroundings, incomplete mixing of substances, and temperature changes in the calorimeter itself. It is important for scientists to account for these potential errors in order to obtain accurate results.

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