List of chemistry mnemonics


A mnemonic is a memory aid used to improve long term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics. This article contains the list of certain mnemonics in chemistry.

Orbitals

Sequence of orbitals

Note: After the k shell, they follow alphabetical order.

Aufbau principle

The order of sequence of atomic orbitals can be remembered by the following.

Periodic table

Periods

Periods 1, 2 and 3

First

Lanthanides

Groups

Group 1 (alkali metals)

Lithium, Sodium, Potassium, Rubidium, Caesium, Francium
Beryllium, Magnesium, Calcium, Strontium, Barium, Radium
Boron, Aluminium, Gallium, Indium, Thallium
Carbon, Silicon, Germanium, Tin, Lead
Oxygen, Sulfur, Selenium, Tellurium, Polonium
Fluorine, Chlorine, Bromine, Iodine, Astatine, Tennessine
Helium, Neon, Argon, Krypton, Xenon, Radon, Oganesson

Abundance of elements on earth's crust

> > > > > > >
'

As they are present in trace quantities they are measured in parts per million''.

Activity series of metals

Potassium>Sodium>Calcium>Magnesium>Aluminium>*>Zinc>Iron>Tin>Lead>*>Copper>Mercury>Silver>Gold>Platinum

Popular Scientists Can Create A Zoo In Low Humid Temperatures, Mercury Silver Gold
Potassium, Sodium, Calcium, Magnesium, Aluminium, Zinc, Iron, Lead, Hydrogen, Copper, Mercury, Silver Gold
Another way to memorize the Reactivity series in order is by Using the Story-Link Memory Technique.
Note that Carbon and Hydrogen are non-metals, used as a baseline.
Li > K > Ba > Sr > Ca > Na > Mg > Al > Mn > Zn > Cr > Fe > Cd > Co > Ni > Sn > Pb

Fluorine > Oxygen > Chlorine > Nitrogen > Bromine > Iodine > Sulfur > Carbon > Hydrogen ≥ Phosphorus

irst ff, oud ow; ing n ome aps, ats, and ants.

Electrochemical series

Potassium > Sodium > Calcium > Magnesium > Aluminium > Zinc > Iron > Tin > Lead > Hydrogen > Copper > Silver > Gold

Redox reactions

A redox reaction is a chemical reaction in which there is a change in oxidation state of atoms participating in the reaction.

Ions

An atom whose oxidation number increases in a redox reaction is said to be oxidized. It is accomplished by loss of one or more electrons. The atom whose oxidation number decreases gains one or more electrons and is said to be reduced. This relation can be remembered by the following mnemonics.
are positively charged ions while anions are negatively charged. This can be remembered with the help of the following mnemonics.
The t in cation looks like a plus sign: "ca+ion".
Cation is positive, anion is negative.
AN OIL RIG CAT:
At the ANode, Oxidation Involves Loss of electrons.
Reduction Involves Gaining electrons at the CAThode.
LOAN - Left Anode Oxidation Negative.
In written representation of galvanic cell, anode is written on the left. It is the electrode where oxidation takes place. It is the negative electrode. Obviously, the opposite properties are found on the cathode. Hence, by remembering LOAN mnemonic, we can arrive at the corresponding properties for the cathode.
LEO says GER:
"Loss of Electrons, Oxidation; Gain of Electrons, Reduction".

Electrodes

An electrode in which oxidation takes place is called an anode while in that which reduction takes place is called cathode. This applies for both electrolytic and electrochemical cells, though the charge on them reverses. The red cat and an ox mnemonics are useful to remember the same.

Diatomic molecules

Molecules exhibiting diatomic structures can be remembered through the following mnemonics.
Hydrogen, Oxygen, Nitrogen, Fluorine, Chlorine, Bromine, Iodine

Hydrogen forms hydrogen bonds with three elements which are nitrogen, oxygen and fluorine. The names of these elements can be remembered by the following mnemonic.
Nitrate, Bromate, Carbonate, Iodate, Chlorate, Chromate, Sulfate, Phosphate

Number of consonants denotes number of oxygen atoms. Number of vowels denotes negative charge quantity. Inclusion of the word "ate" signifies that each ends with the letters a-t-e. To use this for the -ite ions, simply subtract one oxygen but keep the charge the same.

Organic chemistry

Prefixes for naming carbon chains

The prefixes for naming carbon chains containing one to four carbons. For chains containing five or more carbons, the inorganic prefixes are used.
Common names of homogeneous aliphatic carboxylic acids,
Formic, Acetic, Propionic, Butyric, Valeric, Caproic

The sequence of dicarboxylic acids can be remembered with following mnemonics.
Oxalic, Malonic, Succinic, Glutaric, Adipic, Pimelic, Suberic, Azelaic, Sebacic

''m''-directing groups

Note: -NH2,-NHR and NR2 are para directing groups but not -NR3+

E-Z notation for isomers

"E" for enemies. i.e higher priority groups on opposite sides. Z form has higher priority groups on same side.
"Z zame zide" i.e. high priority groups on same side.

Cis–trans isomerism

Cis starts with a C and the functional groups form a C.
Trans, therefore is the other one by default.

Benzene ring: order of substitutes

From R group moving around the ring:

Essential amino acids

Isoleucine, Leucine, Lysine, Arginine, Methionine, Phenylalanine, Threonine, Tryptophan, Histidine, Valine

To remember Krebs cycle ;
Citrate → Aconitate → Isocitrate → Oxalosuccinate → α-Ketoglutarate → Succinate → Fumarate → Malate → Oxaloacetate

To remember the elements necessary for agriculture;
Carbon, Hydrogen, Calcium, Iron, Magnesium, Manganese, Copper, Molybdenum, Chlorine, Boron

For remembering macronutrients;
Carbon, Hydrogen, Oxygen, Phosphorus, Potassium, Nitrogen, Sulfur, Calcium, and Magnesium

C H O N P K Ca Mg S