Gen Chem- Ch. 5 Thermochemistry (1st half)

Main terms & Definition-Some formulas

Thermochemistry

Study of energy changes that accompany chemical reaction

All energy is classified as either _______ or _________

All energy is classified as either Kinetic or Potential

Fundamental principle of thermochemistry:

Energy is released when chemical bonds are formed—- Energy is consumed when chemical bonds are broken

First Law of thermodynamics:

Energy can be converted from one form to another, but it can not be created or destroyed

System

part of universe being studied at a given time

Surroundings

everything else outside of the system being studied

3 types of systems

Open, Closed, Isolated

Open System

when both matter and energy can be exchanged with its surroundings

Ex: uncovered pot of boiling water in a stove

Closed System

Only energy can be exchanged with its surroundings

Isolated System

Neither mass nor energy can be exchanged with its surroundings

Internal energy

Sum of all of the kinetic and potential energy in a system

ΔE = ?

Ef-Ei

If Ef is greater than Ei the system _________ energy and results in a ________ value

(Ef>Ei)

If Ef is greater than Ei the system gained energy and results in a positive value

If Ei is larger than Ef the system ______ energy and results in a ______ value

(Ei>Ef)

If Ei is larger than Ef the system lost energy and results in a negative value

If Ef equals Ei then E= ____

f Ef equals Ei then E= 0

Any increase in energy of the system causes a ________ in the energy of the surroundings

Any increase in energy of the system causes a decrease in the energy of the surroundings

Any decrease in the energy of the system causes a _________ in the energy of the surroundings

Any decrease in the energy of the system causes a increase in the energy of the surroundings

When heat is added to system or work is done on a system the system’s internal energy ________

When heat is added to system or work is done on a system the system’s internal energy increases

Endothermic

process where the system absorbs heat

Exothermic

process where the system loses heat

Extensive property

depends on sample size/mass present 

Ex: mass, volume, energy, heat capacity

Intensive property

sample size/ mass present does not change it

Ex: temp. density, pressure, concentration

State Function

property of a system that depends only on its current state (nitial and final conditions) not on the path taken to reach that state

Ex: temp, pressure, internal energy, enthalpy, volume

Enthalpy

Internal energy + Product of pressure and volume

H+E+PV

ΔE= ?

ΔE= q+w

When q is ______ heat is _________ and surroundings get _______

When q is positive heat is released and surroundings get warmer

When q is ______ heat is _______ and surroundings get ______

When q is negative heat is absorbed and surroundings get cooler 

When w is________ work is done __ the system

When w is positive work is done on the system

When w is ______ work is done ___ the system

When w is negative work is done by the system

When ΔE is ______ there is a net _____ of energy by the system

When ΔE is positive there is a net gain of energy by the system

When ΔE is _______ there is a net _____of energy by the system

When ΔE is negative there is a net loss of energy by the system