Water equivalent of calorimeter

In summary, the conversation discusses finding the water equivalent in kg for a calorimeter with a mass of 0.3 kg and a specific heat of 0.2. After setting up the equation q=cmT and simplifying, the solution is found to be 0.014 kg. However, the answer given is 0.06 kg, which is due to a possible confusion between specific heat and specific gravity in the problem statement.
  • #1
rasen58
71
2

Homework Statement


The water equivalent in kg, of a calorimeter having a mass of 0.3 kg and a specific heat of 0.2 is

Homework Equations


q=cmT

The Attempt at a Solution


I wanted to set cmT = cmT for the water and calorimeter, but I don't know what the equilibrium temperature is.
So what do I do?
 
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  • #2
rasen58 said:
I wanted to set cmT = cmT for the water and calorimeter
That's good. Simplify what you set up, and you're in business.
 
  • #3
Can I cancel out the T's then?
In that case, I would have c1m1 = c2m2
(0.2)(0.3) = (4.186)m2
m2 = 0.014 kg

But the answer says it's 0.06 kg
 
  • #4
rasen58 said:
Can I cancel out the T's then?
Yes.
rasen58 said:
But the answer says it's 0.06 kg
You have met one of many sloppily stated questions you'll run into in your life. "Specific heat" has been conflated with "Specific gravity." Since water has a specific gravity of "One," the author of the question has chosen "One" as the specific heat for water as well. In kcal/kg, yes, but there is no specification of units in the problem statement.

Your understanding is correct, and your application of that understanding is correct.
 

1. What is the water equivalent of a calorimeter?

The water equivalent of a calorimeter refers to the amount of water in the calorimeter that has the same heat capacity as the entire calorimeter system. It is important to know the water equivalent in order to accurately measure the heat released or absorbed in a chemical reaction.

2. How is the water equivalent of a calorimeter calculated?

The water equivalent of a calorimeter can be calculated by multiplying the mass of the calorimeter by its specific heat capacity. This accounts for the heat capacity of the entire system, including the water and the calorimeter itself.

3. Why is the water equivalent of a calorimeter important in experiments?

The water equivalent of a calorimeter is important in experiments because it allows for accurate measurement of the heat released or absorbed in a reaction. Without taking into account the heat capacity of the entire system, the results may be inaccurate.

4. How does the water equivalent of a calorimeter affect the results of an experiment?

If the water equivalent of a calorimeter is not taken into account, the results of an experiment may be inaccurate. This is because the heat capacity of the entire system is not being considered, which can lead to incorrect calculations of the heat released or absorbed in a reaction.

5. Can the water equivalent of a calorimeter change over time?

Yes, the water equivalent of a calorimeter can change over time. This is especially true if the calorimeter is made of a material that is sensitive to temperature changes, as it may expand or contract and affect the overall heat capacity of the system. It is important to regularly calibrate the calorimeter to account for any changes in its water equivalent.

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