Chemistry Definitions

Chemistry glossary AS

The coefficient is the technical term for the ___ written in front of ___ when ___.

The coefficient is the technical term for the number written in front of species when balancing an equation.

A spectator ion is there both ___ and ___ the ___ but is not ___ in the ___.

A spectator ion is there both before and after the reaction but is not involved in the reaction.

In a displacement reaction, one ___ another, less ___, ___ in a ___.

In a displacement reaction, one element replaces another, less reactive, element in a compound.

In a precipitation reaction, an ___ is formed when ___ are ___.

In a precipitation reaction, an insoluble solid is formed when two solutions are mixed.

The molar mass is the ___ per ___ of a ___. It has the symbol ___ and the units ___.

The molar mass is the mass per mole of a substance. It has the symbol M and the units g mol⁻¹.

The Avogadro constant is the ___ of ___ in ___ of a ___. It has the value ___ × ___ and the symbol ___.

The Avogadro constant is the number of particles in one mole of a substance. It has the value 6.02 × 10²³ mol⁻¹ and the symbol L.

A mole is the ___ of ___ that contains the ___ of ___ as the ___ of ___ in exactly ___ of ___.

A mole is the amount of substance that contains the same number of particles as the number of carbon atoms in exactly 12 g of ¹²C.

A hydrate is a ___ containing ___ of ___, represented by formulae such as CuSO₄___5H₂O .

A hydrate is a compound containing water of crystallisation, represented by formulae such as CuSO₄•5H₂O .

The theoretical yield is the ___ of a ___ in a ___, assuming ___ and ___.

The theoretical yield is the maximum possible mass of a product in a reaction, assuming complete reaction and no losses.

The actual yield is the ___ obtained in a ___.

The actual yield is the actual mass obtained in a reaction.

The percentage yield is the ___ the ___, expressed as a ___.

The percentage yield is the actual yield divided by the theoretical yield, expressed as a percentage.

Atom economy is the ___ of the ___ the ___ of the ___ of ___ the ___, expressed as a ___.

Atom economy is the molar mass of the desired product divided by the sum of the molar masses of all the products, expressed as a percentage.

The empirical formula is the ___ of ___ of each ___ in a ___.

The empirical formula is the smallest whole-number ratio of atoms of each element in a compound.

The molecular formula is the ___ of ___ of each ___ in a ___.

The molecular formula is the actual number of atoms of each element in a molecule.

The molar mass is the ___ per ___ of a ___. It has the symbol ___ and the units ___.

The molar mass is the mass per mole of a substance. It has the symbol M and the units g mol⁻¹.

The molar volume is the ___ occupied by ___ of ___. This is normally___ dm³ or ___ cm³ at ___.

The molar volume is the volume occupied by 1 mol of any gas. This is normally 24 dm³ or 24 000 cm³ at r.t.p.

A solute is a ___ that is ___.

A solute is a substance that is dissolved.

A solvent is a ___ that ___ a ___.

A solvent is a substance that dissolves a solute.

A solution is a ___ in a ___.

A solution is a solute dissolved in a solvent.

The mass concentration (of a ___) is the ___ (in ___) of the ___ the ___ of the ___.

The mass concentration (of a solution) is the mass (in g) of the solute divided by the volume of the solvent.

The molar concentration (of a ___) is the ___ (in ___) of the ___ the ___ of the ___.

The molar concentration (of a solution) is the amount (in mol) of the solute divided by the volume of the solution.

Parts per million (ppm) is the ___ of ___ of ___ in ___ of another ___. It is a ___ used to describe ___. Usually, ‘parts’ refers to ___ of ___, or to ___ of ___.

Parts per million (ppm) is the number of parts of one substance in one million parts of another another substance. It is a measure used to describe concentration. Usually, ‘parts’ refers to masses of both substances, or to volumes of both substances.