Two metal rods, one silver and the other copper, are both immersed at

In summary: If you had simply multiplied the thermal conductivity of each material by the time it took for heat to flow through them in a minute, you would get the answer. However, it is not clear what the thermal conductivity of silver and copper is, so you need to find that out first.
  • #1
chemistrymole
17
0

Homework Statement


Two metal rods, one silver and the other copper, are both immersed at one end in a steam chamber at a temperature of 100°C. The other end of each one is in an ice water bath at 0°C. The rods are 5.0 cm long and have a square cross-section that is 2.0 cm on a side. No heat is exchanged between the rods and the surroundings, except at the ends. How much total heat flows through the two rods each minute? The thermal conductivity of silver is 417 W/m • K, and that of copper is 395 W/m • K.


Homework Equations


I think it is H = (k*A*DT)/L


The Attempt at a Solution


I plugged each k separately and got 226 and 248 which are none of the answer choices.
 
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  • #2
No idea what is the correct approach, but I am not surprised what you did doesn't yield a correct answer.

Assuming two copper rods, how much total heat would you expect?
 
  • #3
The formula is OK. Check your calculations. Or show them here.
 
  • #4
I don't think this is your only problem but it's "a" problem...

The formula gives the power in Watts but the question asks..

"How much total heat flows through the two rods each minute?"

.. which would be a figure in joules.

I say it's not the only problem because I got different values for the power in watts in each rod.
 
  • #5
The problem asks for the heat that flows in 2 minutes. Once you have the power you can find the energy.
But the OP did not specify the units for the two values he got so is not clear what quantities they are supposed to represent.
 
  • #6
chemistrymole said:

Homework Statement


Two metal rods, one silver and the other copper, are both immersed at one end in a steam chamber at a temperature of 100°C. The other end of each one is in an ice water bath at 0°C. The rods are 5.0 cm long and have a square cross-section that is 2.0 cm on a side. No heat is exchanged between the rods and the surroundings, except at the ends. How much total heat flows through the two rods each minute? The thermal conductivity of silver is 417 W/m • K, and that of copper is 395 W/m • K.


Homework Equations


I think it is H = (k*A*DT)/L


The Attempt at a Solution


I plugged each k separately and got 226 and 248 which are none of the answer choices.

Your formula is OK if

H = heat RATE (not heat), W
k = thermal conductivity, W/m
A = area, m^2
DT = temperature difference = 100C
L = length of rod, m

Obviously, the total heat rate is the sum of the heat rate of each bar. Then, heat = heat rate times time. Unit of heat is the Joule in SI units. Joules = watts x seconds.

Your answers are way, way too low.

@nasu: the question asks for the total heat conducted over 1 minute, not 2.
 

What happens when two metal rods, one silver and the other copper, are both immersed?

When two metal rods, one silver and the other copper, are both immersed in a solution, a chemical reaction occurs between the metal ions in the solution and the metal atoms in the rods. This results in the transfer of electrons between the rods, causing them to act as electrodes.

Why are silver and copper commonly used as electrodes in scientific experiments?

Silver and copper are commonly used as electrodes in scientific experiments because they are both highly conductive metals. This means that they are able to easily transfer electrons, making them ideal for use in electrical circuits or reactions.

How does the placement of the metal rods in the solution affect the chemical reaction?

The placement of the metal rods in the solution can affect the rate and extent of the chemical reaction. If the rods are placed closer together, the reaction will occur more quickly as there is a shorter distance for electrons to travel. If they are placed further apart, the reaction may be slower or may not occur at all.

What factors can influence the outcome of the chemical reaction between the two metal rods?

The outcome of the chemical reaction between the two metal rods can be influenced by a variety of factors, such as the concentration of ions in the solution, the temperature, and the surface area of the rods. Other external factors, such as the presence of impurities or contaminants, may also affect the reaction.

Can the chemical reaction between the metal rods be reversed?

In most cases, the chemical reaction between the metal rods cannot be reversed. However, the rods can be removed from the solution and the reaction will eventually stop. The products of the reaction can also potentially be separated through various methods, but the original metal rods cannot be fully restored to their original state.

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