Constant-Pressure Calorimetry

Jules Bruno
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now constant pressure Kalorama tree is associated with our coffee cup cal or emitter. Now we're going to say here, it uses the coffee cup cal or emitter to determine he transfers occurring in a liquid solution. Now a cup, coffee cup caliber mature is basically an insulated styrofoam cup with a lid and we're gonna say we call it constant pressure because the calorie meter measuring heat is open to the atmosphere where pressure is going to be fixed. So here we're gonna take a look at the images provided to us. We're gonna start out with our coffee cup calorie meter here on the left, when we look at this coffee cup calorie meter, we're gonna say it has some key portions to it. One of them being this thermometer given to us on top. So that's gonna measure my temperature difference. Then we're gonna have here are styrofoam cover or styrofoam top here. This portion just represents the styrofoam cup itself. In here we have our water and then finally here we have our stir when we place the heated object inside of here, we're gonna be able to measure the amount of heat that's being released. Now realize here when it comes to the constant cup on constant pressure cal or emitter and this coffee cup calorie meter. We have formulas that are associated with it. We're gonna say when both the liquid and calorie meter absorb heat from the hot object. We get the heat lost by the object. So minus q plot equals plus he gained by the water plus the heat also gained by the Calgary emitter. Now we can expand this a little bit further, we're gonna say expanding them to their heat capacity formulas where Q equals M. Cat, we're gonna have Q lost is minus M. Cat. Q. Gained by the water is positive and cat. And remember for the cow limiter, the mass of it is usually unknown. So we ignore its mass within our formula. So it just becomes the heat capacity of the cal or emitter, which is capital C. Times change in temperature. So that becomes our equation for constant pressure kalorama tree, it's going to be minus M. Cat equals plus M. Cat. Plus the specific will the heat capacity of the calorie meter times its change in temperature.