Quantitative Aspects of Chemical Change Flashcards
Definition of a mole
Unit for the amount of substance
Definition of relative atomic mass
Value that compares the mass of one atom of an element with the mass of one atom of Carbon-12
Definition of relative formula mass
The sum of the atomic masses of all of the atoms in its formula for an ionic substance
Definition of molecular mass
The sum of all of the atomic masses of all of the atoms in its formula for a covalent substance
Definition of molar mass
Mass of one mole of a substance
Equal to the molecular mass of a covalent substance and equal to the formula mass of an ionic substance
Unit for number of moles
mol
Unit for mass
g
Unit for molecular mass
g/mol
Unit for number of particles
Molecules
Unit for volume
dm³
Definition of concentration
Number of moles of solute per cubic decimeter of solution
Unit for concentration
mol.dm³
Definition of a titration
A solution of known concentration (standard solution) is used to find out the concentration of an unknown solution
Definition of empirical formula
Simplest whole number ratio of elements in a compound
Steps for a stoichiometric calculation
- Write a balanced chemical equation
- Work out the number of mols of the given substance
- Use molar ratios to work out mols of the unknown substance
- Determine the mass/volume/concentration of the unknown substance
Definition of limiting reagents
The substance that is used up completely in a reaction
Definition of percentage purity
How much of a sample, by mass, is actually of a specific compound/element
Definition of yield
How much product is formed / how much you get
Definition of Avogadro’s number
Amount of particles contained in one mole of a substance
Definition of molar gas constant
One mole of any gas occupies the same volume at the same temperature and pressure
