Year 12 definition list

Homework set on Tuesday 12/12/2023 Title: Create electronic or physical flashcards for your 50 key definitions of the course so far. Description: Create electronic or physical flashcards for your 50 key definitions of the course so far. All 50 key words can be found within the attached document and were provided by your teacher. Bring this work to your lesson for checking by your teacher. Chemistry - 12A/Ch1 - Mr R Frankis Linked note is an attachment

Acid

A substance that donates hydrogen ions (H+) in a chemical reaction.

Addition reactions

Reactions where two or more substances combine to form a single product.

Alkali

A soluble base that releases hydroxide ions (OH-) in a chemical reaction.

Anhydrous

A substance that does not contain water molecules.

Atom economy equation

A calculation that measures the efficiency of a chemical reaction by comparing the mass of desired product to the total mass of reactants.

Atomic orbital

A region of space around an atom where there is a high probability of finding an electron.

Base

A substance that accepts hydrogen ions (H+) in a chemical reaction.

Covalent bond

A chemical bond formed by the sharing of electron pairs between atoms.

Concordant results

Multiple measurements or observations that agree closely with each other.

Curly arrows in reaction mechanisms

Symbols used to represent the movement of electron pairs during a chemical reaction.

Dative covalent bond

A covalent bond where both electrons are provided by one atom.

Disproportionation

A redox reaction where a single substance is simultaneously oxidized and reduced.

Electronegativity

A measure of an atom's ability to attract electrons towards itself in a chemical bond.

Elimination reactions

Reactions where a molecule loses atoms or groups of atoms to form a double bond or ring structure.

First ionisation energy

The energy required to remove one electron from an atom in its gaseous state.

Heterolytic fission

The breaking of a covalent bond where both electrons are taken by one of the atoms involved.

Homologous series

A series of organic compounds with the same functional group and similar chemical properties, but with increasing carbon chain length.

Homolytic fission

The breaking of a covalent bond where each atom retains one of the shared electrons, forming two radicals.

Hydrated

A substance that contains water molecules.

Hydrogen bonding

A strong intermolecular force between a hydrogen atom bonded to an electronegative atom and another electronegative atom.

The ideal gas equation (including units)

PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature (in Kelvin).

Ionic bonding

A chemical bond formed by the transfer of electrons from one atom to another, resulting in the formation of ions.

Limiting reagent

The reactant that is completely consumed in a chemical reaction, limiting the amount of product that can be formed.

Localised electrons

Electrons that are confined to a specific region around an atom or within a covalent bond.

London forces

Weak intermolecular forces caused by temporary fluctuations in electron distribution, resulting in temporary dipoles.

Metallic bond

A chemical bond formed by the attraction between positive metal ions and delocalized electrons.

Oxidising agent

A substance that causes another substance to lose electrons, undergoing reduction itself.

Percentage yield equation

(Actual yield / Theoretical yield) x 100%, where actual yield is the amount of product obtained in a reaction and theoretical yield is the maximum amount of product that could be obtained.

π-bond

A covalent bond formed by the overlap of p orbitals above and below the bonding axis.

Precipitation reaction

A reaction where two soluble substances react to form an insoluble solid (precipitate).

Qualitative analysis – the test for ammonium ions

A test using sodium hydroxide and heating, resulting in the release of ammonia gas, tested with litmus paper.

Qualitative analysis – the test for carbonate ions

A test using dilute hydrochloric acid, resulting in the release of carbon dioxide gas put this gas through lime water to test if it is carbon dioxide.

Qualitative analysis – the test for halide ions

A test using nitric acid then adding some silver nitrate, resulting in the formation of a precipitate white = chloride ions, cream = bromide ions, yellow = iodide ions. If further testing is required add dilute ammonia to show presence of clorine ions, then add concentrated ammonia in a fume cupboard to show presence of Bromine ions.

Qualitative analysis – the test for sulfate ions

A test using dilute hydrochloric acid and then add a few drops of aqueous barium chloride, resulting in the formation of a white precipitate.

Radical

A highly reactive atom or group of atoms with an unpaired electron.

Reducing agent

A substance that causes another substance to gain electrons, undergoing oxidation itself.

Relative atomic mass

The average mass of an atom of an element, taking into account the abundance of its isotopes.

Relative isotopic mass

The mass of an isotope of an element relative to the mass of carbon-12.

σ-bond

A covalent bond formed by the overlap of orbitals along the bonding axis.

Salt

An ionic compound formed by the reaction between an acid and a base.

Second ionisation energy

the energy required to remove a second electron from each ion in 1 mole of gaseous 1+ ions, resulting in gaseous 2+ ions.

Standard conditions

Standard conditions

Conditions of temperature and pressure used as a reference point for comparing gases. Standard conditions are defined as 0 degrees Celsius (273.15 Kelvin) and 1 atmosphere of pressure (101.325 kilopascals).

Standard solution

A solution with a known concentration used in chemical analysis to determine the concentration of an unknown substance.

Stereoisomers

Different molecules with the same chemical formula, but arranged differently in space. They have identical connectivity but differ in the arrangement of atoms. Stereoisomers can be classified as either enantiomers or diastereomers. Enantiomers are non-superimposable mirror images, while diastereomers are not. Stereoisomers have distinct physical and chemical properties.

Strong acid

A flashcard for "Strong acid":

• A substance that fully dissociates in water

• Releases H+ ions in high concentration

• Has a low pH value (less than 3)

• Examples include hydrochloric acid (HCl) and sulfuric acid (H2SO4)

• Used in various industries and laboratories for their corrosive and reactive properties.

Structural isomers

Structural isomers: Isomers with the same molecular formula but different structural arrangements. They have different connectivity and may exhibit different physical and chemical properties.

Substitution reactions

Type of chemical reaction where an atom or group of atoms in a molecule is replaced by another atom or group of atoms.

Unsaturated

A type of chemical compound that contains double or triple bonds between carbon atoms, allowing for additional atoms to bond. Unsaturated compounds have fewer hydrogen atoms than saturated compounds and are typically more reactive.

Flashcard: Water of crystallisation

Water molecules that are chemically bound to a crystalline compound. They can be removed by heating, resulting in the compound's dehydration.

Weak acid

A weak acid is a substance that partially dissociates in water, releasing a few hydrogen ions (H+). It has a low tendency to donate protons and a higher tendency to remain in its molecular form. Weak acids have a pH value greater than 7 and are less reactive compared to strong acids.