Please enable JavaScript.
Coggle requires JavaScript to display documents.
Topic 9 (CHEM) - The mole and chemical calculations (Determining Empirical…
Topic 9 (CHEM) - The mole and chemical calculations
Moles (mol) = Particles / (6 x 10^23)
Moles (mol) = Mass (g) / Molar Mass (g/mol)
Determining Empirical Formula
Step 1: Write down the mass of each element (g)
Step 2: Write down the molar mass of each element (g/mol)
Step 3: Divide mass / molar mass to get moles (mol)
Step 4: Divide each element's mol by the smallest number
Write chemical formula according to ratio (rounded off)
Simplify to get empirical formula
Determining Limiting Reactant
Find number of mol of both reactants (A and B for e.g.)
Assume A is used up completely
(No) of mol of A reacts with (No) of mol of B
Thus, mol of B needed to react = (No of mol of A) * ratio (given the calculated number of mol of B)
If the mol of B needed to react is >= the calculated no of mol of B, then B is the limiting reactant.
Otherwise, A is the limiting reactant
Moles (mol) = Volume of gas (dm3) / (24) ==> R.T.P.
Moles (mol) of
solute
= Volume (dm3) of
Solution
x
Concentration (mol/dm3) of
Solution
Mass of
solute
(g) = Volume (dm3) of
Solution
x
Concentration (g/dm3) of
Solution
Conversion from mol/dm3 to g/dm3
mol/dm3 x MOLAR MASS = g/dm3
Percentage Yield = Actual Yield / Theoretical Yield
Percentage Purity = Mass (pure sample) / Mass (Impure sample)