Chapter 3 - Amount of substance Flashcards
How do you calculate the amount of moles of a substance?
moles= mass / mr
What is the molecular formulae?
The number of atoms of each element in a molecule
What is the empirical formulae?
The simplest whole number ratio of the atoms of each element in a compound.
What assumptions are made in water of crystallisation calculations?
- All of the water has been lost (heat to a constant mass)
-There is no further decomposition of the salt when heated further
What is the equation for volume, moles and concentration?
moles = volume (dm^3) X concentration (mol dm ^-3)
what is a standard solution?
A solution of a known concentration.
How do you prepare a standard solution?
Dissolve an exact mass of the solute in a solvent to make up a solution of an exact volume
What is the ideal gas equation?
pV = nRT
pressure = pa
volume =m^3
temperature = K (c -> k = +273)
What is the equation for % yield?
actual / theoretical X100
What is atom economy?
A measure of how well atoms have been utilised
How do you calculate atom economy?
mr of product wanted / total mr of all products X100
