Grade 12 Chemistry (Last Concept map ;)

Organic Chemistry

Amines

nitrogen

naming

Screen Shot 2022-06-20 at 10.19.32 AM

add -bi, -tri to -amine to indicate multiple of same type of alkyl

add suffix -amine

each alkyl group in alphabetical order

ammonia molecules

amines

hydrogen is replaced by an alkyl chain

Screen Shot 2022-06-20 at 10.14.54 AM

3 possible covalent bonds

1 alkyl chain

2 alkyl chain

3 alkyl chain

primary amine

secondary amine

tertiary amine

Screen Shot 2022-06-20 at 10.16.54 AM

esters

H2O as a product

formed by

reaction between

alchool

carboxylic acid

are carboxylic acids

OH is replaced with O and alkyl

OCO

Screen Shot 2022-06-20 at 10.07.19 AM

naming

first

second

Screen Shot 2022-06-20 at 10.11.44 AM

alchool

carboxylic acid

anoic acid --> oate

ol --> yl

carboxylic acid

Screen Shot 2022-06-20 at 10.04.19 AM

named using suffix -anoic acid

COOH group

Screen Shot 2022-06-20 at 10.01.51 AM

contain carboxyl group

C=O

contains hydroxyl group

OH

the end of chain

most polar molecule

aldehydes and ketones

lower boiling points than alchools

ketone

Screen Shot 2022-06-20 at 9.58.18 AM

-one

carbonyl group in the middle of the chain

not at the end

aldehyde

Screen Shot 2022-06-20 at 9.57.13 AM

carbonyl group at the end of carbon chain

suffix -al

alcohols and ethers

ether

naming ethers

Screen Shot 2022-06-20 at 9.53.07 AM

use -oxy to the end of name

shorter chain first

shorter chains name

organic molecules that contain oxygen bonded to carbon

can't participate in hydrogen bonding

hydrogen replaced by alkyl group

alchool

OH group

hydroxyl

Screen Shot 2022-06-20 at 9.45.34 AM

naming alcohols

-ol

number of carbons closest to functional group

OH

Alkyl chains

Screen Shot 2022-06-20 at 9.40.48 AM

-yl

not main chain

alkane chain branched from alkane chain

same prefixes as alkanes

number longest carbon chain

lowest number at the bonds

then the alkyl chain

functional groups

grouped together when a group of atoms contribute in an interesting way

carbon bonded to a more electronegative atom

double/triple bond

carbon chains are unsaturated

kinks in chains

C=O

C-OH

C-Cl

impact properties of molecules

naming alkenes and alkynes

more than 3 carbon atoms

count the carbons

count closest to the bond

Screen Shot 2022-06-20 at 9.33.16 AM

same as alkanes

first part

how many carbons in the longest chain

Screen Shot 2022-06-20 at 9.23.16 AM

second part

double bond

triple bond

-ene

-yne

Screen Shot 2022-06-20 at 9.30.29 AM

Screen Shot 2022-06-20 at 9.29.32 AM

alkanes

alkanes have double or triple bonds

name it

count number of carbon atoms in longest chain

add -ane to the end

this will be prefix

Screen Shot 2022-06-20 at 9.24.47 AM

first part

how many carbons in longest chain

Screen Shot 2022-06-20 at 9.23.16 AM

second part

if there is any bonds in molecule

drawing organic molecules

lewis structures

referred as structural formula

Screen Shot 2022-06-20 at 9.16.32 AM

condensed structural formula

CH3CH2CH3

shorthand

Screen Shot 2022-06-20 at 9.20.57 AM

each end of a line is a carbon atom

no symbols

each line represents a bond

each carbon has hydrogen atoms bonded to it

carbon bonds

hydrocarbons

Screen Shot 2022-06-20 at 9.16.32 AM

only hydrogen and carbon atoms

organic compound

compounds based on carbon chains

carbon

triple

from covalent bonds

single

double

structural isomers

molecular formula can be the same as another compund

structure is always different

non-polar

longer the chain...higher boiling point

halides

hydrogen atom switch with halogen

unsaturated

stereoisomers

different atom arrangement

same backbone

isomers

cis

same side of double bond

trans

opposite side of double bond

markovnikov's rule

how atoms add to the double bond

"hydrogen halide or water molecule reacts with an alkene, the hydrogen atom will generally bond to the carbon atom in the multiple bond that has the most hydrogen atoms already bonded to it"

aromatic

unsaturated

ring structure

naming

alkyl group

-benzene

benzene ring that lost a hydrocarbon

phenyl group

"phenyl" as substituent

properties

non-polar

insoluble in water

polymers

built from monomers

monomer is repeating units to form polymer

polyethene

homopolymer

formed by reaction of simple monomer

Screen Shot 2023-06-16 at 11.48.19 AM

simplest one

copolymer

2+ monomers combined

addition or condensation reaction

protiens

silk

natural

living things

starch

cellulose

RNA + DNA

synthetic

look at natural polymers for properties

sourced from plants

polyester

rubber (tires)

disposing synthetic properties

harsh

don't break down quickly

engineering biodegradable synthetic materials

addition

very long

organic molecule

result of addition reactions

unsaturated carbon-carbon bonds

plastic bags

radical

break double bond

Screen Shot 2023-06-16 at 11.58.58 AM

continues to get next monomer

Screen Shot 2023-06-16 at 12.00.13 PM

chain continues

Screen Shot 2023-06-16 at 12.00.38 PM

continues for the number depicted by 'n'

Screen Shot 2023-06-16 at 12.01.48 PM

plastics

can be moulded

under heat/pressure

thermoplastics

from petrochemicals

properties

unreactive

stable single bonded

weak intermolecular forces

flexible when heated (usually)

heat increases molecular motion

unwanted plastics

condensation polymers, can be biodegradable

cross linking

form networks

allow hydrogen bonding between chains

more cross linking = tighter the chains are linked together

Screen Shot 2023-06-16 at 12.24.24 PM

condensation

very long

organic molecule

result of condensation reactions

2 monomers with 2 functional groups

ester or amide links

polyesters

monomers with 2 functional groups

-OH group

-COOH group

Screen Shot 2023-06-16 at 12.28.23 PM

must attach to end

ester linkage

growing chain. monomer keep attaching

polyester + water

2 hydroxyl groups and 2 carboxylic acid groups

dacron

PET

condensation copolymer

polyamides

condensation reaction

alcohol and carboxylic acid

nylon lab

natural

cellulose

polysaccharides

monosaccharide

ketone or aldehyde

with hydroxyl substituents

large polymer of monosaccharides

bond of glycogen

peptides

2+ amino acids linked

same as amide linkage

protiens

amino acids

-COOH

-NH2

Hydrogen

R-aditional group

structure

primary structure

Screen Shot 2023-06-16 at 12.46.19 PM

secondary structure

hydrogen bonding between oxygen and carbonyl

shape is important

nucleic acid

DNA

polymer in cells nucleus

RNA

polymer in cell cytoplasm

makes up DNA and RNA

nucleotides

5-carbon sugar

nitrogen-containing organic base

phosphoric acid molecule

DNA or RNA combines with phosphoric acid

quantum matter

electron

J.J. Thomson

negative pole repelled the ray

all atoms must contain electrons

electrodes

plum pudding model

randomly Screen Shot 2023-06-16 at 1.33.26 PM

radioactivity

spontaneous decay or disintegration of nucleus

uranium produces image on plate

elements that emit radiation

alpha, betta, gamma

atom

rutherford

alpha particle at gold foil

mostly empty space

nucleus

dense centre of atom with positive charge

proton

positive subatomic particle

neutron

neutral subatomic particle

isotopes

same number of protons different neutrons

nearly all the volume of an atom

radioisotopes

emits radioactive gamma rays

alpha or beta particles

nature

light

electromagnetic radiation

maxwell's theory

continuous wavelengths that form spectrum

photoelectric

electrons emitted by matter

then absorbs energy

Hertz

frequency of light was important in determining energy of emitted electrons

Planck's

matter can gain or lose energy

E=nhf

6.63x10^-34

measured and is a constant

quantum

burst/packet of energy

photons

unit of light energy

fundamental particle

electron can escape a surface

electron absorbs photon

atomic spectra

spectroscopy

analysis of spectra to determine properties of source

measure intensity of light

no light=spectrum

spectrum of hydrogen atom

advancing atomic theory

excited hydrogen atoms

release energy by emitting light in wavelengths

emission spectrum

electromagnetic radiation emitted by an atom

when atom is returned to a lower energy state from a higher one

continuous spectrum

contains all wavelengths in specific region

line spectrum

contains only wavelengths characteristic of the element being studied

unique to each element

when excited electrons move lower energy level

they emit a photon of light

transition

electron moves up or down energy level

Bohr model

first 18 elements

2, 8, 18 electrons

does not fully describes structure

electrons can't actually orbit nucleus

flame test lab

mechanical model

schrödinger's standing wave

electron has wave lengths

electron bound to a nucleus

resembles a standing wave Screen Shot 2023-06-16 at 8.35.55 PM

nodes

starting and ending of each cycle

antinode

amplitude of wave

must be whole number

applied standing waves to hydrogen atom

n=1,2,3,4...

orbitals

region around nucleus where electron= high probability

heisenberg's uncertainty principle

impossible to know

exact position

exact speed

describe probability of finding electron in location

wave function

mathematical probability of finding an electron in a certain region of space

electron isn't moving around the nucleus in a circle

electron probability density

finding electron at given point

derived from wave equations

determine shape of orbitals

also a distribution

quantum mechanical model

electrons can be in different orbitals

based on quantum theory

probability for the location of electrons

quantum numbers

describe quantum mechanical properties of orbitals

principal (n)

describes size

describes energy

atomic orbital

whole-number values

spaces between atomic shells aren't equal

n increases, energy required for an electron to occupy orbital increases as well

subshells

s, p, d, f

different shapes

secondary (l)

shape of orbital

from 0 to n-1

n=1 only s orbitals exist

n=3 there can be s, p and d orbitals

no stable element higher than subshell f

magnetic (ml)

orientation

relative to other orbitals

whole number between +1 and -1 including 0

ml=number of orbitals possible

Screen Shot 2023-06-18 at 10.46.22 AM

shapes/orientations of orbits

2s and 3s contain separate areas of 0 probability

nodes

p orbitals

not spherical

2 lobes separated by node at nucleus

xyz system

d orbitals

l=2

occur when n=3+

spin (ms)

+1/2 or -1/2

electron can spin in 1 of 2 opposite directions

pauli exclusion

"in a given atom, no 2 electrons can have same set of 4 quantum numbers (n,l,ml,ms))"

Atomic structure and periodic table

elements arranged according to way electrons arrange around the nuclei of atom

multi-electronic

determines chemical behaviour

kinetic energy of electrons as moving about nucleus

potential energy attraction between nuclei and electrons

potential energy repulsion between 2 electrons

can make aproximations

more effective electrons go through shielding electrons, lower energy of electrons in said orbital

electron configuration

location of electron energy levels

number of electrons in energy level

aufbau principle

theory that an atom is built by addition of electrons

fill orbitals starting at lowest available orbital

Screen Shot 2023-06-19 at 12.38.13 PM

examine electron configuration of elements

Screen Shot 2023-06-19 at 12.39.43 PM

describes relative energies of the electrons in an atom

hund's rule

orbitals of same energy

lowest energy configuration

pauli exclusion

maximum number of unpaired electrons

unpaired electrons are represented as having parallel spins

put electron in each p,d,f before paring them

all unpaired electrons should have the same spin

electron configuration

use periodic table to determine number of electrons in the atom or ion

assign electrons by main energy level

then by sublevel

using an energy-level diagram or an aufbau diagram

distribute electrons by main energy according to hund's rule

fill each sublevel before starting next sublevel

for anions

for cations

remove electrons

add electrons

periodic table

valence electrons 4s has lower energy than 4d orbitals

outermost principal quantum level of atom

transition metals

highest level are d orbitals

chromium is an exception

2 half s and d

4s^13d^5

lower energy

more stable

copper is an exception

n+1 fill before nd orbitals

chemical bonding

ionic bond

electrostatic attraction between oppositely charged ions

strong attraction

higher electronegative in one

crystal lattice

examine the valance electron configuration

isoelectric

having the same number of electrons per atom, ion, or molecule

molecular elements

hydrogen atoms are certain distance apart

covalent bonding

proton-electron force

proton-proton balance

electron-electron forces

chemical bond in which atoms share bonding electrons

bonding electron pair

pair involved in bonding

found in space between atoms

lewis theory of bonding

atoms and ions are stable

full valence shell

stable electron

when paired

chemical bonds

create full valence shell

sharing electrons

exchange of electrons

non-metals and metals

covalent bond

coordinate covalent bonding

lewis structure

Screen Shot 2023-06-19 at 2.08.21 PM

arrangement of covalent electrons

polyatomic ion

duet rule

hydrogen and period 2 metals

octet rule

atoms tend to form most stable substances

surrounded by 8 electrons in valence shell

Screen Shot 2023-06-19 at 2.10.29 PM

lone electron pair

valance electrons that are localized to given atom

exceptions

fewer or more than 8 electrons around central atom

electrons involved are from 1 atom

H+ with ammonia forms covalent bond with remaining pair of electrons

electrons come from nitrogen

Screen Shot 2023-06-19 at 2.20.06 PM

3-D structure

arrangement of ions or atoms making pure substance

determines how pure substance will behave

VSEPR theory

determines geometry of molecule

electron pairs far apart as possible

electron-pair repulsion

occurs between electron pairs

positioned as far apart as possible

minimize repulsive force between electron pairs

2 bonding pairs

far apart as possible

Screen Shot 2023-06-19 at 2.27.22 PM

3 bonding pairs

farthest at 120 degrees

Screen Shot 2023-06-19 at 2.29.01 PM

lone pairs dont play factor in determining shape

Screen Shot 2023-06-19 at 2.30.10 PM

multiple bonds

double and triple

shorter

stronger

pure substances are the same single or triple

1 more bonding pair of electrons

work

ionic and molecules

phoshine fails

add more rules

bond polarity

non-polar covalent bond

electrons are shared equally

2 identical molecular atoms

hydrogen

nitrogen

chlorine

polar covalent bond

electrons aren't shared equally

1 atom atracts more than other

electronegativity

ability to attract shared electron to itself

different elements have different electronegativities

bonds are all mixtures of covalent and ionic character

spectrum values

Screen Shot 2023-06-19 at 3.43.22 PM

diople

separation of positive and negative charges in a region

arrow points to negative end

Screen Shot 2023-06-19 at 3.45.02 PM

molecular polarity

polar

non-polar

net dipole

only non-polar bonds

bond dipole sum of zero

Screen Shot 2023-06-19 at 3.47.49 PM

Screen Shot 2023-06-19 at 3.48.12 PM

geometric shape

determines polarity

Screen Shot 2023-06-19 at 3.48.50 PM

quantum mechanics

hybridization

electron density decreases uniformly

further from the center

electrons are concentrated in centre of benzene

valence bond theory

atomic orbitals overlap to form new orbital

with pair of opposite-sign electrons

lowest energy state is obtained

2s orbitals

covalent

1s orbitals now have opposite signs

Screen Shot 2023-06-19 at 4.00.34 PM

any unfilled orbital can overlap with another unfilled

Screen Shot 2023-06-19 at 4.01.11 PM

hybrid orbitals

process of forming hybrid orbitals

combination of 2 different orbitals

carbon atom

1s and 3 p

end with 4sp^3

Screen Shot 2023-06-19 at 4.07.22 PM

all identical to each other

Screen Shot 2023-06-19 at 4.08.08 PM

tetrahedral arrangement

can form bonds

Screen Shot 2023-06-19 at 4.09.21 PM

cant form bonds

Screen Shot 2023-06-19 at 4.09.10 PM

triple and double covalent bonds

between unpaired electrons from

s orbitals

p orbitals

sp

sp^2

sp^3

directly overlap

sigma bond

s orbitals

p orbitals

multiple bond

pi bond

a bond that is formed when sides of the lobes of 2 orbitals overlap

Screen Shot 2023-06-19 at 4.32.41 PM

sp and p orbitals

90 degrees

triple bond

1 sigma

2 pi bonds

Screen Shot 2023-06-19 at 4.33.53 PM

intermolecular forces

causes 1 molecule to interact with another

bond

van der waals forces

chemical bond within molecule

between 2 molecules

diople diople

london dispersion

hydrogen bonding

polar

position positive and negative ends near each other

attractive and repulsive

1% as strong as ionic and covalent

weaken rapidly

strong diople-diople

hydrogen bonded to

oxygen

nitrogen

fluorine

partially negative atom on nearby molecule

very high boiling points

remain liquids even at high temperatures

non-polar molecules

increase as molecular mass increases

all undergo this

electrons move around nucleus

non-symmetrical electron distribution

weak

dosent last long

polarization

form a dipolar charge distribution

liquids

not compressible like gas

higher densities

surface tension

resistance of liquid to increase surface area

capillary action

spontaneous rising of a liquid in a narrow tube

cohesive

adhesive

solids

composite material

composed of 2 or more distinct materials that remain separate from each other when solid

ionic crystals

crystal lattice

packed positive and negative ions

hard

brittle solids

electricity

high melting points

metallic crystals

closely packed atoms

electrostatic

free-moving electrons

not all have same properties

electron sea theory

electrons move freely

around positive nuclei

metallic bonding

hold nuclei and electrons together

metals

molecular crystals

composed of molecules

intermolecular forces keeping together

complex

neutral molecules

not conduct current

covalent network crystals

interwoven network

high melting point

super hard

buckyball

60 carbon atoms

hollow cage

carbon nanotubes

carbon atoms

graphite rolled in cylinder

energy

energy

thermochemistry

energy changes

physical or chemical change

ability to do work

amount of energy transformed over a distance (j)

potential

body or system

position

composition

kinetic energy

object doe to motion

relesed

combustion of gasoline

products have less potential energy than reactants

thermal energy

kinetic and potential

heat

transfer of thermal to a cooler object

temperature

average kinetic energy

law of conservation of energy

"cannot be created or destroyed"

no new energy can be made

chemical system

reactants and products being studied

open

closed

energy can leave

calorimeter

matter and energy can leave

matter cannot leave

isolated

matter and energy cant leave

endothermic

exothermic

releasing energy

absorbing energy

nuclear energy

fussion

2 nuclei combine

fission

neutron to split atomic mass

heat capacity

(c)

amount of thermal energy required to raise temperature of 1 g by 1 degree celsius

Screen Shot 2023-06-19 at 5.54.42 PM

calorimetry

measuring thermal energy change

chemical or physical change

calorimeter

measure thermal energy changes

well insolated chamber

temperature change of water

change of thermal energy

bomb calorimeter

calculations

q=mc(delta T)

delta T=T final - T inital

Screen Shot 2023-06-19 at 5.59.02 PM

enthalpy

total amount of thermal energy in substance

delta H

change

energy released/absorbed

h>0

h<0

endothermic

exothermic

molar

change associated with physical, chemical, nuclear change

Screen Shot 2023-06-19 at 6.01.41 PM

bond energies

dissociation energy

energy required to break given chemical bond

positive value

type of atom dependent

as number of bonds increase

bond length shortens

hess's law

change in enthalpy in chemical process is independent

change in enthalpy is same regardless of conversion

"change of conversion of reactants to products is the same whether the conversion occurs in several steps"

Screen Shot 2023-06-19 at 6.06.20 PM

rules

reversed chemical reaction

reverse delta H sign

formation

change in enthalpy that accompanies formation of 1 mol of a compound in standard states

Screen Shot 2023-06-19 at 6.14.47 PM

(1) remains unchanged

(2) is reversed

usually solids

sometimes gasses

exothermic

endothermic

sources

fossil fuels

crude oil

coal

natural gas

efficiency

ratio of energy output to the energy input of any system

click to edit

click to edit

reactions

rate

change in concentration of reactant

or product of a chemical reaction

chemical kinetics

area of chemistry that deals with rates of reactions

measuring

observing appearance of a product

tracking changes in gas volume

colour

mass

pH

electrical conductivity

intensityope

n vessel gas substance produced

pH meter paper or indicator

average reaction rates

change in reactant or product concentrations over given time interval

Screen Shot 2023-06-19 at 6.31.20 PM

always positive number

graph

rise over run

Screen Shot 2023-06-19 at 6.32.25 PM

instantaneous rate of reaction

rate of a chemical reaction at a single point in time

stoichiometric rate relationships

negative means consumption

positive means formation

nature

chemical property

relates to the behaviour of pure substance

concentration

rate of reaction increases at higher concentrations of reactants

surface area

reactants are more than one state of matter

greater surface area

faster the rate

temperature

reaction increases with temperature

double every 10 degree celsius increase and halved at every decrease of 10

presence of catalyst

substance that alters the rate of chemical reaction without permanent change

polyethene

uses metal catalyst

biological catalyst

living thing

enzymes

heterogeneous catalyst

reactants and catalyst are in different physical states

homogeneous catalyst

same physical states

collision theory

chemical reactions occur only if reactants collide

need proper orientation

enough kinetic energy

Screen Shot 2023-06-19 at 6.45.33 PM

activation energy

minimum energy

activated complex

unstable arrangement of atoms

partially formed and unformed bonds

maximum potential energy point

transition state

alternative pathway for reaction

lower activation energy Screen Shot 2023-06-19 at 6.48.53 PM

rate law

mathematical expression that allows calculation of reaction rate as function of concentration

Screen Shot 2023-06-19 at 6.51.40 PM

constant

empirically

unique for single reaction at temperature

total order of reaction

sum of the exponents in rate law equation

steps

measure

test

compare

mechanics

series of elementary steps produce chemical reaction

involves entity collision

cant be simpler steps

Screen Shot 2023-06-19 at 6.56.05 PM

cant be written from overall balanced equation

can be written from elementary step balance

chemical systems

equilibrium systems

until reactants run out

chemical

reactants and products reach constant concentrations

dynamic

balance between forward and reverse

occur simultaneously

as concentration increases

reactants decrease

Screen Shot 2023-06-19 at 7.03.44 PM

position

relative concentrations of reactants and products

dynamic

reversible reaction

proceeds in both forward and reverse directions

closed system

final concentrations of gases at equilibrium are the same

determine concentration

ICE table

Screen Shot 2023-06-19 at 7.06.11 PM

constant

K

defining law for given system

law

chemical state at equilibrium

temperature dependent

Screen Shot 2023-06-19 at 7.08.06 PM

quantitative changes

chatelier principle

"chemical system at equilibrium is disturbed by a change in a property, system adjusts in a way that opposes change"

equilibrium shift

change in concentration

restore state

reversible reactions

shift when disturbed

energy as reactant or product

Screen Shot 2023-06-19 at 7.12.35 PM

Screen Shot 2023-06-19 at 7.12.46 PM

endothermic reactions

thermal energy removed

reactants decreased

exothermic reaction

toward product

to the right

ideal gas

no size

no attraction

obeys all gas laws

partial pressure

if gas was occupying the whole volume by mixture

inert gas

collisions that won't result in chemical reaction

quantitative changes

predict shifts

reaction quotient

product of concentration

Q

not necessary at equilibrium

instantaneous concentration

occur together at particular moment

solubility

quantity of solute

dissolves in solvent

ionic compounds

in water form dynamic equilibrium

solubility equilibrium

dynamic

between solute and solvent

acids and bases

theorys

arrhenius

acid produce hydrogen ions

base produce hydroxide ions

bronsted-lowry

acid is hydrogen ion donor

base is hydrogen acceptor

hydronium ion

water molecule that has accepted hydrogen ion

hydroxide is responsible for basic properties

pairs

conjugate acid

base accepts proton

conjugate base

acid loses hydrogen ion

acid-base pair

related by donating and accepting protons

amphiprotic

able to donate

or accept proton

acid and base

acid ionization

Screen Shot 2023-06-19 at 7.28.59 PM

strong and weak

acid

strong

ionizes almost 100%

base

weak

partialy ionizes

oxyacid

acidic hydrogen atom is attatched to oxygen atom

organic

contains carbon

oxygen

hydrogen atoms

carboxylic acid

weak

partially reacts to produce hydroxide

strong

dissociates completely

water

acid or base

in the same reaction

autoionization of water

hydrogen atom transfer from one molecule to another

titration

lab preformed

addition of precise volumes

used to determine concentration of substance

buffer systems

buffer

aq solution

conjugate acid-base pair

constant pH

electrochemistry

oxidizing agents

reducing agents are oxidized when they reduce something

oxidizers are causing something to become oxidized

themselves reduced

cells and batteries

secondary

primary

fuel

battery

group of 2 or more galvanic cells connected in series

galvanic cell for which the reactants are continuous

cell that cant be recharged

needs an external source of electricity

can be recharged

activity series

more keen on loosing something less keen on gaining something

strongest oxidizing agents are weakest reducing agents

Screen Shot 2022-06-20 at 10.55.28 AM

mnemoic devices

LEO says GER

OIL RIG

redox

simultaneously

reduction process

oxidation process