Chemistry: Chapter 17 Study Guide

thermochemistry
The study of energy changes that occur during chemical reactions and changes in state.

chemical potential energy
The energy stored in the chemical bonds of a substance.

heat
Energy that transfers from one objects to another because of a temperature difference between them.

system
Part of the universe on which you focus your attention.

surroundings
Everything else in the universe.

law of conservation of energy
This is the idea that in any chemical or physical process, energy is neither created nor destroyed.

endothermic process
A process where heat is absorbed from the surroundings (example: a campfire giving heat to people around it).

exothermic process
A process where heat is released to its surroundings (a person who is running and giving off heat).

heat capacity
The amount of heat needed to increase the temperature of an object exactly 1 degree Celsius.

specific heat
The amount of heat it takes to raise the temperature of 1g of the substance 1 degree Celsius.

heat
This always flows from a warmer object to a cooler object.

calorie and joule
Heat flow is measured with these units.

calorie
The amount of heat needed to increase the temperature of 1g of water 1 degree Celsius.

1000 calories
How many calories make up 1 dietary Calorie?

mass and chemical composition
The heat capacity of an object depends on these 2 things.

4.184
1 cal = ? joules

specific heat
(heat) / (mass x change in temperature) is the formula for?

heat capacity
The greater the mass of an object, the greater its ________.

calorimetry
The precise measurement of the heat flow out of a system for chemical and physical processes.

calorimeter
The device used to measure the absorption or release of heat in chemical or physical processes.

enthalpy
The heat content of a system at constant pressure.

thermochemical equation
A chemical equation that includes the enthalpy change.

heat of reaction
The enthalpy change for the chemical equation exactly as it is written.

heat of combustion
The heat of reaction for the complete burning of 1 mole of a substance.

equal
In calorimetry, the heat released by the system is _______ to the heat absorbed by its surroundings.

molar heat of fusion
The heat absorbed by one mole of a solid substance as it melts to a liquid at a constant temperature.

molar heat of solidification
The heat lost when one mole of a liquid solidifies at a constant temperature.

molar heat of vaporization
The amount of heat necessary to vaporize one mole of a given liquid.

molar heat of condensation
The amount of heat released when one mole of vapor condenses at the normal boiling point.

molar heat of solution
The enthalpy change caused by dissolution of one mole of substance.

Hess’s law of heat summation
This states that if you add two or more thermochemical equations to a given final equation, then you can also add the heats of reaction to give the final heat of reaction.

standard heat of formation
The change in enthalpy that accompanies the formation of one mole of a compound from its elements with all substances in their standard states at 25 degrees Celsius.

solution
During the formation of a _______, heat is either released or absorbed.

Hess’s Law
This allows you to determine the heat of reaction indirectly.