Unit 1- Formulae Flashcards
Define elements
simplest chemicals, cannot be broken down into any more simpler molecules
Define compounds
Chemicals containing two or more elements chemically bonded
Define atoms
smallest particle of an element
Define molecules
A chemical containing two or more atoms chemically bonded
Define Ion
An atom or group of atoms which are electrically charged due to the gain or loss of electrons
Define molecular formulae
Shows the number of atoms of the different elements in one molecule of a compound
Define Empiracal formulae
Shows the simplest whole number ratio of the atoms of different elements in a compound
What is the formulae for Relative atomic mass?
- Ar
- RAM = average mass of an atom/moles
What is the Relative molecular mass?
- Mr
- used to compare the masses of different molecules
What is molar mass?
- Amount of a substance in moles
- M
- 1 mole of an element is equal to its relative atomic mass in grams
How to calculate amount in a substance?
- Referred to as Mol
- Mol= Mass/Molar mass
- Mol=g/g per mole
What is the avagadro constant?
- Referred to as L
- Number of atoms, molecules in moles of any molecules
- Number of atoms = mol x avagadro constant
How to calculate ppm?
- 1ppm = (mass of solute/mass of solution) x 10^6
How to calculate concentration?
- Measured in mol per dm^3
- Concentration = mass of a solute/volume of a solution
How to calculate volume?
Volume= moles x molar volume (normally 24)
