What is the change in density if the water is heated to 85oC?

AI Thread Summary
The discussion focuses on calculating the change in density of water when heated from 4°C to 85°C, using a coefficient of volume expansion of 2.10x10^-6/°C. The initial density of water is given as 1.00x10^3 kg/m³. To find the change in density (Δρ), the formula Δρ = -αρΔT is suggested, where α is the coefficient of volume expansion and ΔT is the temperature change. Participants emphasize using a standard mass and volume to simplify calculations, ensuring that the initial mass and volume factors cancel out. The solution involves calculating the final density based on the expanded volume and initial density.
Jayhawk1
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Here's the problem:

The density of water at 4oC is 1.00x103kg/m3. What is the change in density if the water is heated to 85oC? Remember that the change will be the final density minus the initial density. Assume a coefficient of volume expansion of 2.10x10-6/oC.

Now, I have tried using a standard mass of 1000KG and solving the problem that way, however I am way off... please help
 
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Jayhawk1 said:
Here's the problem:

The density of water at 4oC is 1.00x103kg/m3. What is the change in density if the water is heated to 85oC? Remember that the change will be the final density minus the initial density. Assume a coefficient of volume expansion of 2.10x10-6/oC.

Now, I have tried using a standard mass of 1000KG and solving the problem that way, however I am way off... please help
SOLUTION HINTS:
By definition:
{Coefficient of Volume Thermal Expansion} = α = (-1/ρ)(Δρ/ΔT)
::: ⇒ Δρ = -αρΔT
Use values given in problem statement for terms on the right to calculate "Δρ".


~~
 
Jayhawk1 said:
Here's the problem:

The density of water at 4oC is 1.00x103kg/m3. What is the change in density if the water is heated to 85oC? Remember that the change will be the final density minus the initial density. Assume a coefficient of volume expansion of 2.10x10-6/oC.

Now, I have tried using a standard mass of 1000KG and solving the problem that way, however I am way off... please help

Calculate the volume expansion assuming an initial volume V_0. Add that to the initial volume to find a final volume. Multiply the initial density times V_0 to get an initial mass expressed in terms of V_0. Divide that mass by the new volume. The V_0 factors will all divide out. It will work.
 
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