17.1 The Flow of Energy
The study of energy changes that occur during chemical reactions and changes in state.
What is thermochemistry?
The precise measurement of the heat flow into or out of a system for chemical and physical processes.
What is calorimetry?
When a vapor condenses, ____ is released.
What is heat?
Define Hess's Law of Heat Summation.
if you add the thermochemical equations to each step to give you a final equation for the reaction.
process of absorbing heat from surroundings
What endothermic process?
The energy stored in the chemical bonds of a substance
What is (chemical) potential energy?
The heat content of a system at constant pressure
What is enthalpy?
A liquid that absorbs heat at its boiling point becomes a ____
What is vapor?
the change in enthalpy that accompanies the formation of a mole of a compound from its elements with all substances in their standard states
What is standard heat of formation?
process that releases heat to surroundings
What is exothermic process?
Energy that transfers from one object to another because of a temperature difference between them.
What is heat?
The heat of reaction for the complete burning of one mole of a substance
What is heat of combustion?
heat lost when one mole of a liquid is converted to a solid
What is molar heat of solidification?
What does Hess's Law allow you to do?
To determine the heat of reaction indirectly
energy cannot be destroyed or created.
What is the law of conservation of energy?
What determines the amount of energy stored in the substance?
The types of atoms and their arrangement in the substance determine the amount of energy stored in the substance.
How can the enthalpy change be written in a chemical equation?
In a chemical equation, the enthalpy change for the reaction can be written as either a reactant or a product.
heat absorbed by one mole of a substance as it melts to a liquid at a constant temperature
What is molar heat of fusion?
How can you calculate the heat of reaction when it cannot be directly measured?
Hess's law allows you to determine the heat of reaction indirectly using other known heats of reactions.
the enthalpy change for the chemical equation exactly as it is written
What is heat of reaction?
What direction does heat flow in?
Heat always flows form a warmer object to a cooler object. If two objects remain in contact, both objects will be the same temperature.
How is the heat released by the surroundings related to the heat absorbed in a system?
In calorimetry, the heat released by the system is equal to the heat absorbed by its surroundings.
heat lost when one mole of a liquid solidifies
What is molar heat of solidification?
Are diamonds made from heat? Do their forming involve thermochemistry?
What is YES and YES?
.238 cal equals how many Joules?
What is 1 Joule?