Thermodynamics

Mere som dette

E.M. Spectrum

af Peter Clark

Information System Concepts

af Krishnan Subramanian

The characteristics of living things

af Lady Moreno

Carb Concept Cards

af lolo lolo

Thermodynamics

Type in the name of your subject.

Change in Gibbs Free Energy, ΔG

TΔSuniverse is denoted by ΔG

Laws of Thermodynamics

Second Law

the entropy of the universe increases in spontaneous processes and remains unchanged during equilibrium processes. (∆S universe = ∆S system + ∆S surroundings)

spontaneous process, ∆S universe = + ve

ΔG = ∆H system - T∆S system

equilibrium process, ∆S universe = 0

First Law

energy can be converted from one form to another but cannot be created or destroyed. Based on the law of conservation or energy.

Spontaneity

Add detailed notes about each lecture, so that when the time comes to prepare for exams, you will have an easier and quicker overview.

How to determine spontaneity?

Change in entropy change ΔS

Change in enthalpy ΔH

- both endothermic and exothermic reaction can be spontaneous - sign of ∆H alone is insufficient to predict spontaneity in every process/reaction.

Spontaneous Process

require a 'pus' to get started

Add a list of questions to help you recap your lecture.

occurs without continuous input of energy

Write down if there are things you would like to discuss or clarify with your teacher or colleagues in relation to this topic.

spontaneous

ball moving down a slope

non-spontaneous

water freezing at 25 °C 1 atm

occurs under a specific set of conditions

Add a short description of the lecture.

Entropy

Review your resource requirements and tick off the devices you will need as well as their availability. Add others, if necessary.

Standard Entropy Change ΔS

Add other resources:

∆rxnS = S (product) - S (reactant)

how to determine ΔS?

by comparing the number of particles of the reactants and products

decrease in the number of particles

increase in the number of particles

by comparing the physical states of the reactants and products

gas to solid

decrease in the number of possible arrangements

solid to gas

increase in the number of possible arrangements

definitions

Select as needed:

possible arrangements or configurations of a system

Examples

least number of possible outcomes

solid state

most number of possible outcomes

gaseous state

"disorder' of a system

Enthalpy

Type in all the info you would like to know about this subject. If there is something you don't know yet, no problem! You can fill in the blanks along the way.

Standard Enthalpy Change

Did your teacher present the objectives of this course? Write them down and add anything else that might help you reach these objectives.

standard bond dissociation enthalpy

bond forming

energy released

ΔH bond forming is -ve

bond breaking

energy is absorbed

ΔH bond breaking is +ve

standard enthalpy change of formation, Δf H°

Δf H° of an element & 7 diatomic elements (H2, N2, O2, F2, Cl2, Br2, l2)

Δf H° = 0 kJ/mol

one mole of compound is formed from its element in their reference states

standard enthalpy of reaction, Δrxn H°

∆rxn H° = Sum of Δf H° (product) - Sum of Δf H° (reactant)

unit of Δrxn H° is kJ

only be used with the Δf H° of reactants and products

standard enthalpy change ΔH°

reaction at the same specific temperature

how to determine ΔH?

Type in the name of your teachers and teacher assistants, plus any details you should know about them.

products have more energy than reactants

Heat absorbed to surroundings

endothermic reaction

+ve ΔH

products have lesser energy than reactants

Heat released to surroundings

exothermic reaction

-ve ΔH

definition

Add details about your course.

Enthalpy change ΔH - amount of heat released or absorbed by a chemical system when a chemical reaction occurs at constant pressure.