Chapter 3 Amount Of Substance Flashcards
What is the amount of substance?
Number of particles in a substance, measured in moles.
How many particles are there in one mole?
Avogadro constant, 6.02x10^23
What is molar mass?
Mass per mole of a substance
What are the different formulaes?
Molecular formulae: number of atoms in each element in a molecule
Empirical formulae: the simplest whole number ratio of atoms of each element in a compound
What is water of crystallisation?
Water molecules that are part of crystalline structure
What is the molar gas volume?
Volume per mole of the gas molecule at stated temperature and pressure
What is RTP?
Room temperature and pressure
101kPa and 293K
24dm^3mol^-1
What is the ideal gas equation?
pV=nRT
What is stoichiometry?
The balancing number that give the ratio of the amount, in moles, of each substance.
What is the theoretical yield?
The maximum possible amount of product.
Why is theoretical yield difficult to achieve?
Reaction may not have gone to completion.
Other reactions may have taken place alongside the main reaction.
Purification of the product may result in loss of some products.
How do we calculate percentage yield?
percentage yield= actual yield/ theoretical yield
What is the limiting reagent?
The reactant that is not in excess and is completely used up first that stops the reaction.
What is the atom economy?
Measure of how well atoms have been utilised.
atom economy= sum of molar masses of desired products/ sum of molar masses of all products
How do we make sure there is no water left in the molecule?
Heat to a constant mass
No further decomposition
