Calorimetry is the science of determining the quantity of heat moved to or from a material in a process by measuring the heat exchanged with the environment using a calorimeter. A coffee cup calorimeter is made up of a cup, a thermometer, and a reactant that are all put within the cup.
As a result, the heat detected in such a device corresponds to the change in enthalpy. A coffee cup calorimeter is often used for solution-based chemistry, which requires little or no volume change.
As a result, although the heat is precisely equal to the enthalpy change (H) in this situation, it will also be about equal to the change in internal energy (U) due to the little amount of work (assuming there are no gas reactants or products).
Isobaric calorimetry is the more technical word for this sort of calorimetry. The moniker “coffee-cup” stems from the fact that this experiment is usually done in a basic styrofoam cup. A styrofoam cup forms a suitable adiabatic wall, allowing us to quantify all of the heat emitted or absorbed by the reaction within the cup.
The heat capacity of a coffee cup calorimeter is often assumed to be the same as the calorimeter’s water. It’s possible, though, that both the “hardware” and the water heat capacity have been measured, and you’re treating it as bomb calorimetry. Regardless, most coffee-cup calorimeters contain almost no hardware (it’s a styrofoam cup! ), so you may disregard it. As a result, the interest equation is:
It’s worth noting that in this case, the heat of the reaction is believed to be completely absorbed by the temperature change in the water. This is why the mass of the water, the specific heat capacity of the water, and the temperature change can all be used to calculate the heat.
The heat is equal to the change in enthalpy, or ΔH, since this measurement is made at constant pressure (isobaric). Take special attention with the symbol on ΔH. Heat is transferred from the reaction to the calorimeter and vice versa. As a result, a rise in temperature indicates that the reaction was “exothermic,” and ΔH is negative.
In contrast, if the temperature lowers throughout the process, it must be endothermic, therefore ΔH must be positive.
What sort of system is the coffee cup calorimeter, and what does it entail in terms of energy transfer? Image result
Heat is exchanged between the “system” and the “surroundings,” and this heat is what is measured. A coffee cup calorimeter is made up of a cup, a thermometer, water, and a reactant that is put inside the cup. A coffee cup calorimeter is a constant pressure calorimeter, unlike a bomb calorimeter.
Because it permits heat to be transferred, a bomb calorimeter is a closed system. Although this system is insulated, it is not one of the three primary categories of systems: closed, open, or isolated. Any transmission of matter or energy would be impossible in an isolated system.
https://bowie1983book.com/ will answer what kind of system is the coffee cup calorimeter considered, and what does that mean in terms of energy transfer?