Chapter 5 Chemistry Notes
Chapter 5 Notes
The study of energy and its transformations is called thermodynamics.
An aspect of thermodynamics that deals with the relationships between chemical reactions and energy changes involving heat is called thermochemistry.
5.1 The Nature of Energy
Energy is defined as the capacity to do work or produce heat.
Work is the energy used to cause an object with mass to move.
Heat is the energy of an object that causes its temperature to increase.
Kinetic and Potential Energy
Kinetic energy is the energy caused by motion.
Kinetic energy = 0.5 (mass) (velocity)squared
Potential energy is the energy by virtue of an object’s position relative to other objects. [Occurs when there is a force acting on an object]
Potential energy = (mass) (height) (gravity = 9.8m/s squared)
A force is any kind of push or pull exerted on an object.
Kinetic energy can get converted into potential energy or vice-versa.
Electrostatic Potential energy rises from the interactions between charged particles.
Electrostatic Potential energy = (k (Q1) Q2))/ D
Q1 and Q2 are usually the order of magnitude of charge on an electron
(1.6 x 10 to the power negative 19)
Chemical energy of substances if due to the potential energy stored in the arrangement of atoms in a substance
Units of Energy
S.I unit of energy is the joule but usually kilojoules are used.
Famous non S.I unit for energy is calorie. 1 calorie is the amount of heat required to raise the temperature of 1g of water by 1 degree celsius
System and Surroundings
The portion we single out to study is called the system.
Everything else is called the surroundings
Only energy can be exchanged between system and surroundings. Not matter!
Transferring Energy: Work and Heat
Work = Force x Displacement
5.2 The First Law of thermodynamics
The first law of thermodynamics states that energy is conserved (it is neither created nor destroyed)
Internal Energy
The internal energy of a system is the sum
The study of energy and its transformations is called thermodynamics.
An aspect of thermodynamics that deals with the relationships between chemical reactions and energy changes involving heat is called thermochemistry.
5.1 The Nature of Energy
Energy is defined as the capacity to do work or produce heat.
Work is the energy used to cause an object with mass to move.
Heat is the energy of an object that causes its temperature to increase.
Kinetic and Potential Energy
Kinetic energy is the energy caused by motion.
Kinetic energy = 0.5 (mass) (velocity)squared
Potential energy is the energy by virtue of an object’s position relative to other objects. [Occurs when there is a force acting on an object]
Potential energy = (mass) (height) (gravity = 9.8m/s squared)
A force is any kind of push or pull exerted on an object.
Kinetic energy can get converted into potential energy or vice-versa.
Electrostatic Potential energy rises from the interactions between charged particles.
Electrostatic Potential energy = (k (Q1) Q2))/ D
Q1 and Q2 are usually the order of magnitude of charge on an electron
(1.6 x 10 to the power negative 19)
Chemical energy of substances if due to the potential energy stored in the arrangement of atoms in a substance
Units of Energy
S.I unit of energy is the joule but usually kilojoules are used.
Famous non S.I unit for energy is calorie. 1 calorie is the amount of heat required to raise the temperature of 1g of water by 1 degree celsius
System and Surroundings
The portion we single out to study is called the system.
Everything else is called the surroundings
Only energy can be exchanged between system and surroundings. Not matter!
Transferring Energy: Work and Heat
Work = Force x Displacement
5.2 The First Law of thermodynamics
The first law of thermodynamics states that energy is conserved (it is neither created nor destroyed)
Internal Energy
The internal energy of a system is the sum