Amount of substance Flashcards
Definition for the amount of substance n
Number of particles in a substance.
What is the unit of amount of substance
the Mole ‘mol’
Number of particles in one mole/ Avogadro’s constant
6.02 x 10^23
What is one mole based on
The amount of atoms in 12g of carbon 12.
Define Molar Mass
Mass per mole
Units of molar mass
gMol^-1
Define Molar Mass Volume
Gass volume per mole, 24dm^3 for one mole
Molar mass volume units
DM^3 mol^-1
Empirical formula
Simplest whole number ratio of atoms of each element in a compound
Molecular Formula
The actual number of atoms of each element in a compound.
Define hydrated (crystals)
Water molecules are part of the crystals crystalline structure.
Define water of crystallisation
Water molecules found in hydrated crystals which are a part of the crystalline structure
Define anhydrous (crystals)
A salt without water of crystallisation
Define a salt
A compounds consisting of negatively and positively charged ions in a lattice formation.
What is the ideal gas equation
pV = nRT
What circumstances are there for the ideal gas equation pV = nRT
- There must be no intermolecular forces between gas molecules.
- Elastic collisions between gas molecules.
- The particles must have 0 volume.
- random motion
Reasons for not getting a theoretical yield (actual yield)
- The reaction may of not gone till completion
- Other (side) reactions may of occurred along side the main reaction.
- Purification of the product may of resulted in loss of some product.
How to calculate the percentage yield
percentage yield = actual yield/ theoretical yield x 100%
Define atom economy
The atom economy of a reaction is a measure of how well the atoms have been utilised
Calculate atom economy
atom economy = Sum of desired products (mr) / sum of all products (mr) x 100%
Benefits of a high atom economy
Cheaper to produce and more sustainable to produce less waste products
