Equations Flashcards
Amount of substance
“n” used to count the number of particles in a substance
Unit for amount of substance
Mole
Avogadro constant
The number of particles per mole, 6.02 x 10^23 mol-1
Molar mass
The mass per mole of a substance, units g mol-1
Empirical formula
The simplest whole number ratio of atoms of each element present in a compound. You divide the mass of the elements by their mr, then divide that by the smallest number to get the ratio. You may have to multiply to get a whole number and not a decimal.
Molecular formula
The number and type of atoms of each element in a compound. You divide the mr of the actual compound by the mr of the empirical formula. You then multiply the empirical formula to get this number.
Hydrated
Water molecules are part of the crystalline structure
Water of crystallisation
The water molecules which are part of the crystalline structure
Anhydrous
When the water molecules are no longer part of the crystalline structure
How to find the water of crystalline
Calculate the moles of water by dividing the mass change by the mr of water. You divide the anhydrous compound by its mr to find its moles. You find the ratio between the two moles to figure out the water of crystallisation.
Moles, mr, mass
moles = mass/ mr
Moles, volume, concentration
concentration = moles / volume
moles, volume
moles = volume (dm) /24 moles = volume (cm)/24000
Ideal gas equation
PV = nRT pressure (pa) n=mol volume m^3 Temperature K R= ideal gas constant 8.31
Nitrate
NO3 -
