How much heat is transferred and at what temperature?

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Homework Help Overview

The problem involves heat transfer in a system consisting of a copper bowl, water, and a copper cylinder. The scenario describes the heating of water and the boiling of a portion of it, raising questions about the calculations of heat transfer to both the water and the bowl, as well as the initial temperature of the cylinder.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to clarify which mass of water to use in calculations, questioning whether to account for the mass of water that turns to steam. They also seek to understand if the energy transferred refers only to the liquid water or includes the steam as well.

Discussion Status

Some participants provide guidance on the calculations needed to determine the heat transferred to the water and the bowl. There is a recognition of the need to consider both the heating of the water and the energy required for the phase change to steam. Multiple interpretations of the problem are being explored, particularly regarding the mass of water and the definition of energy transfer.

Contextual Notes

The problem includes specific constraints such as the initial temperatures, masses of the components, and the phase change of water to steam, which are under discussion but not resolved.

ice87
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A 150g copper bowl contains 220g of water. Both bowl and water are at 20 degrees C. A very hot 300g copper cylinder is dropped into the water. This causes the water to boil, with 5g being converted to steam, and the final temperature of the entire system is 100 degrees C. a) how much heat is transferred to the water? b) how much to the bowl? c)what is the original temperature of the cylinder?

I get the jist of this problem but what i don't know is what to sub in for the mass of water, do i use 220g? or 215g since 5 is boiled away? Something else i don't get is when it says the energy transferred to the water, does that mean the energy transferred to the liquid water and the steam? or just the liquid?
 
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You have two components - liquid water and gaseous water. The liquid water was merely heated while the gaseous water (steam) underwent a phase change --- which requires additional energy! :)
 
Heat has to be transferred to the water before it becomes steam! Calculate the heat necessary to raise 220 g of water to from 20 C to 100 C. Then calculate the heat necessary to change 5 g of water into 5 g of heat. That's the "heat transferred to the water".

Also then calculate the heat necessary to raise 150 g of copper from 20 C to 100 C.

Finally, if the total amount of heat you just calculated were put back into the 300 g copper cylinder, it would raise the temperature of that cylinder from 100 C to what?
 
ah yes, it is as i suspected.
 

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