Energy required to heat a house with insulated walls

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Homework Help Overview

The discussion revolves around calculating the energy required to heat a well-insulated house containing a volume of air at a specific temperature. The problem involves the properties of a diatomic gas and the application of heat capacity at constant pressure.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the use of heat capacity and the temperature difference, while questioning how to determine the number of moles and the values of pressure and the gas constant. There is confusion regarding the temperature values and the constants involved in the calculations.

Discussion Status

Some participants have offered guidance on assumptions, such as using standard atmospheric pressure and clarifying the use of constants. Multiple interpretations of the problem are being explored, particularly regarding the calculation of the number of moles and the application of the ideal gas law.

Contextual Notes

There is uncertainty regarding the values of pressure and the gas constant, as well as the interpretation of temperature changes. Participants are working within the constraints of the problem as presented, without additional information on the number of moles or specific constants.

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I have an problem that can not solve, any help would greatly appreciated.

A house has well-insulated walls.It contains a volume of 100m3 of air at 300K. Calculate the energy required to increase the temperature of this diatomic gas by 2 degree celsius. Assume it is heating at constant pressure and use Cp=7R/2.
 
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What's stopping YOU from solving it? You've got a heat capacity, you've got a temp difference. What more could you want? Oh, yeah, maybe the number of moles?
 
Thanks Dick, that's problem I couldn't solve for the number of moles. I know the formula

PV=nRT, the problem here, how can I find P & R? P is constant? T is 275 right? or Delta T is 275, make me confuse... the answer is:118KJ,236KJ,354KJ,472KJ
I don't get any the right one. please help
 
They are talking about a 'house'. I think you can assume the pressure is 1 atmosphere. You don't 'find' R. It's a constant. You look it up. The problem you quoted says T=300K.
 
Hi Dick,

I wonder "Calculate the energy required to increase the temperature of this diatomic gas by 2 degree celsius. Assume it is heating at constant pressure and use Cp=7R/2."

They asked for the energy required to increase the temperature of this diatomis gas by 2 degree celsius. I got stuck in here.
 
(Change in energy)=(Heat capacity)*(change in temperature)*(amount of stuff). You are already given two quantities on the right side - you just need to find the amount of stuff. Number of moles, remember?
 

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