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Thermochemistry
Topic of chemistry concerning the quantities of heat evolved or absorbed
Term | Definition |
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Calorimetry | the amount of heat involved in a chemical or physical process used to measure amounts of heat transferred to or from a substance. example: Styrofoam in a coffee cup calorimeter is that it reduces the amount of heat exchange between the water in the coff |
Joules | the scientific measurement derived unit of energy, work, and heat. |
calorie | a unit of energy or heat that is the amount of heat required at a pressure of 1 standard atmosphere to raise the temperature of 1 gram of water 1° Celsius. |
Heat | the amount of energy that is transferred from one system to its surroundings because of a temperature difference. example: |
Temperature | quantitative measurement of how hot or cold of a substance or object and the property of matter which reflects the quantity of energy of motion of the component particles |
Entropy | qualitatively measure how much the energy of atoms and molecules become more spread out in a process. example: Melting ice - the individual molecules are fixed and ordered. As ice melts the molecules become free to move therefore becoming disordered |
Enthalpy | the sum of the internal energy and the product of the pressure and volume of a thermodynamic system. example: Fire, heat of solution, boiling, chemical cold packs, freezing |
Endothermic process | reactions that require external energy, usually in the form of heat. example: forming a cation from an atom in the gas phase, evaporation of water |
Chemical energy | the capacity for doing work and contained in the bonds of chemical compounds. example: Coal - the combustion reaction converts chemical energy into light and heat. |
Exothermic process | a reaction that releases energy from the system to its surroundings, in the form of heat. example: condensation of rain from water vapor, rusting iron |
Chemical thermodynamics | the study of the relations between heat, work, temperature, and energy with chemical reactions . |
Kinetic energy | the energy that an object possesses due to its motion. and the energy of mass in motion. example: you walking down the street, and molecules moving in space all have kinetic energy measured in units of Joules (J); one Joule |
Specific heat | the quantity of heat required to raise the temperature of one gram of a substance by one Celsius degree measured in calories or joules per gram per Celsius degree |
Thermal energy | energy generated and measured by heat. example :furnace burns natural gas in a chemical reaction. As the natural gas burns, heat is released causing air molecules to move faster. The temperature of the air increases because they have more thermal energy |
Sublimation | the transition from the solid phase to the gas phase without passing through an intermediate liquid phase. example: dry ice |
Latent heat energy | energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process — usually a first-order phase transition. the flat part of the heat curve |
Energy | the capacity for doing work |