GENCHEM FINALS

Thermodynamics

interconversion of heatand other forms of energy, studying the laws governing energy transfer and the work done by or on systems.

Spontaneuos Process

naturally happening

non spontaneous processes

pinipilit to happen

entropy

thermodynamic quantity measuring how spread out the energy of a system is

chaos measure of DISORSER

Boltzman 1868

inteoduced entropy

microstates

specific arrangements of particles within a system

distribution

each set of similar microstates

second law of thermodynamics

says that entropy of the universe increases in a spontaneous process and remains unchanged in an equilibrium process

Gibbs free energy

opposite of entropy

done

what are the formulas needed for chapter 5? list on a paper

equilibrium

state with no observable changes as time goes by

A<>B (equal rate = equilibrium)

types of equilibrium

1. chemical equilibrium

2. physical equilibrium

chemical equilibrium

chemists are ONLY interested here

rates of forward and reverse reactions are equal

physical equilibrium

equilibrium between two phases of the same substance is called

vaporization of water in a closed container because ang number ng H20 molecules na naga vaporize at ang number ng naga return sa liquid ay equal

example of physical equilibrium

Cato Guldberg and Peter Waage

formulated the equilibrium constant formulas

reaction quotient Qc

this is for reactions that havent reached equilibrium and predict its direction

1. small

2. large

3. left to right

if Qc is less than Kc

1. product concentration is?

2. reactant concentration is?

3. what direction?

1. large

2. small

3. right to left

if Qc is greater than Kc

1. product concentration is?

2. reactant concentration is?

3. what direction?

if Qc is equal to Kc

it is at equilibrium and has no direction to go to anymore

Le Chateliers Principle

states that if an external stress is applied to a system (like change in pressure, concentration, temperature, etc.), the system will adjust in such a way that the system reaches new equilibrium

vegetable kingdom

where can u find most organic acids

Bronsted acid

substance capable of donating a proton

Bronsted Base

substance capable of accepting a proton

Conjugate acid-base pair

two substances that differ only by the presence of a proton

7 (neutral)

pH of pure water (acting as a base/acid it depends)

trulalu

water is a weak electrolyte therefore a poor conductor of electricity UNLESS IONIZED

autoionization of water

a proton is transferred from one water molecule to another to produce a hydronium ion (H₃O⁺) and a hydroxide ion (OH⁻)

1×10^-14

value of Kw

pH

acidity measurement

negative log of the hydrogen ion concentration and is dimensionless

Soren Sorensen 1909

proposed the pH or Power of hydrogen

pOH

basicity measurement

negative log og OH concentration

pH meter

measuring the hydrogen ion concentration, typically in a water-based solution.

yes it can

can pH values be more than 14 and less than 1?

strong acids

strong electrolytes assumed to ionize completely in water

weak acids

most acids are weak, only ionize to a limited extent

strong bases

strong electrolytes that ionize completely in water

weak bases

weak electrolytes

salt hydrolysis

reaction of an anion or a cation of a salt or both with water

this usually affects pH of solution

Buffer solution

has the ability to resist changes in pH upon the addition of either acid or base

solution of weak acid/weak base + salt

buffering capacity

effectiveness of the buffer solution

salt-acid

conjugate base-acid

i’m buffer system can be represented as

electrochemistry

interconversion of electrical energy and chemical energy

electrical energy

most important form of energy

redox

oxidation reduction reaction (spontaneous reactions)

oxidation

LOSS OF ELECTRONS

REDUCTION

GAIN ELECTRONS

Electric current

rate flow of charge

Electric circuit

path where current flows

Electrical Potential

ability of electric field to do work on the charge

Galvanic / Voltaic cells

An electrochemical cell that converts the chemical energy of spontaneous redox reactions into electrical energy

Luigi Galvani

Alessandro Volta

they constructed early versions of galvanic cell devices

Cell voltage / electromotive force (emf)

measure of voltage across the electrodes of a galvanic cell

Battery

a galvanic cell providing direct current at a constant voltage

Dry Cell battery

a cell without a fluid component

Leclanche cell used in flashlights pr radios

The Mercury battery

used extensively in medicine and electronics

contained in a stainless steel cylinder

The Lead storage battery

commonly used in automobiles consisting of 6 identical cells in series

The lithium ion battery

can be recharged hundreds of times without deteriorating making it suitable for phones laptops etc

Fuel Cells

major source of energy but conversion of fossil fuels to electricity is INEFFICIENT

Corrosion

term usually applied to the deterioration of metals by an electrochemical process

rust on iron

tarnish on silver

blue green patina on statue of liberty

examples of corrosion

Electrolysis

process in which electrical energy is used to cause a non spontaneous chemical reaction

MEDYO OPPOSITE NG REDOX..?

electrolytic cell

apparatus for carrying out electrolysis

dental filling discomfort

ang cause nito ay pag nag pa dental filling ka may metal na kasama yung filling at pag like kumagat ka ng aluminum foil na binabalot sa mga pagkain magkakaroon ka ng sharp pain dahil may mapproduce na electricity at mattrigger nila ang sensitive nerves