Chemistry

Cards (16)

Relative formula mass 
The sum of the atomic masses
Symbol for relative formula mass
Mᵣ
Percentage composition equation 
% composition = Mᵣ of element divide by Mᵣ of compound x 100%
Moles equation 
moles = mass ÷ Mᵣ
Empirical formula 
The simplest whole number ratio of atoms in a compound
Empirical formula experimental method
Use a crucible, measure the mass before and after, use the empirical formula calculation
Law of conservation of mass 
The total mass of reactants is the same as the total mass of the products in a reaction.
Closed system 
A reaction in which no chemicals can escape.
Non-closed system 
A reaction in an open flask that takes in or gives out a gas.
Precipitate 
A substance deposited in solid form from a solution.
Concentration equation 
concentration = moles ÷ volume
Units for concentration 
g dm⁻³
Number of particles in one mole
6.02 × 10²³ (Avogadro constant)
One mole of a substance has the mass of... 
the relative formula mass in grams.
Limiting reactant 
The reactant that is completely used up in an reaction
In excess 
The reactant that is not completely used up in a reaction