Calorimeter heat capacity / heat of combustion formulas
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Calorimeter heat capacity / heat of combustion formulas
In Achieve week 3/4 question #12, it says that the formula for heat capacity (C) is C = q/deltaT and the formula for heat of combustion (q) is q = -(C*deltaT)/g, but I thought in lecture we learned that the formulas are C = q/(n*deltaT) and q = g*C*deltaT. Can anyone explain where Achieve got these formulas from?
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Re: Calorimeter heat capacity / heat of combustion formulas
So there are a bunch of different 'versions' of heat capacity that need to be accounted for -- the book gives one version but the lectures give all 3..
To break them down one by one:
C = q/delta(T) this is the empirical version of heat capacity meaning it is dependent on how much heat is there in the substance/how much substance is there as a result.
C = q/(n*delta(T)) This is the molar heat capacity, which means the heat capacity is dependent on the moles of substance there is. It can also be written as Cm which I find makes it clearer, but it is essentially a non-empirical version of heat capacity
C = q/(g*delta(T)) This is the specific heat capacity, which means the heat capacity is dependent on the grams (not moles) of substance there is. It can also be written as Cs.
Finally the formula achieve gave where q = -(C deltaT)/g appears to use the heat capacity of the calorimeter itself rather than the heat capacity of a substance. The general version of this stands as q = - qcal, where q is the heat of the system, and qcal is the heat of the calorimeter or the heat of the surroundings.
To break them down one by one:
C = q/delta(T) this is the empirical version of heat capacity meaning it is dependent on how much heat is there in the substance/how much substance is there as a result.
C = q/(n*delta(T)) This is the molar heat capacity, which means the heat capacity is dependent on the moles of substance there is. It can also be written as Cm which I find makes it clearer, but it is essentially a non-empirical version of heat capacity
C = q/(g*delta(T)) This is the specific heat capacity, which means the heat capacity is dependent on the grams (not moles) of substance there is. It can also be written as Cs.
Finally the formula achieve gave where q = -(C deltaT)/g appears to use the heat capacity of the calorimeter itself rather than the heat capacity of a substance. The general version of this stands as q = - qcal, where q is the heat of the system, and qcal is the heat of the calorimeter or the heat of the surroundings.
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