Chapter 3 Flashcards
Definition of amount of substance
Amount of substance is A dimensionless expression of the number of particles in a sample measured in moles (mol)
What is avagadros constant?
Avagadros constant is the number of particles per mol - 6.02 x10^23
What is molar mass?
Molar mass is the mass per mol measured in gmol ^-1
It is the same as relative atomic mass
How do you find the number of molecules/ particles in something?
Multiply the moles by avagadros constant and then multiple by the number of atoms in what your finding
What is molar gas volume?
Molar has volume is the gas volume per mol (24 dm3)
Definition of molecular formula
Molecular formula is the number and type of atoms of each element in a molecule
Definition of empirical formula
Empirical formula is the simplest whole number ratio of atoms of each elect present in a compound
What is a hydrated salt?
A hydrated salt is a crystalline compound containing water molecules.
What is an anhydrous salt?
An anhydrous salt is a crystalline compound containing no water molecules.
What is the water of crystallisation?
The water of crystallisation are the water molecules that are part of the crystalline structure of a compound
How to find the formula of a hydrated salt
1) weigh an empty crucible
2) add the hydrated salt and weigh again
3) heat crucible on a Bunsen burner
4) leave to cool then weight crucible and anhydrous salt
5) analyse using results to find the moles and use stoichiometry to find the formula
Mass=
Mass = mol x mr
Volume (dm3)=
Volume = mol x molar has volume (24)
Concentration =
Concentration= mol/ volume (dm3)
Ideal gas equation =
PV= nRT
