quantitative chemistry Flashcards
mole definition (1)
amount of substance with the same number of particles as carbon-12
mole value (1)
6,02x10^23 (mol/n)
molar mass (1)
relative atomic mass of substance (g.mol^-1/M)
mole formula
n=m/M
percentage composition (1)
percentage of each element in a compound
percentage composition of an element formula (1)
M(element)/M(compound) x 100
molar volume of gas formula (1)
n = V/Vm
volume of any gas at STP (1)
22,4dm^3
empirical formula (1)
simplest formula of a compound in ratio
molecular formula (1)
true formula of compound based on number of atoms in physical substance
how to get empirical formula (3)
- assume 100g sample using percentage comp.
- find no. of mol in each element
- simplify ratio using n of moles
how to get molecular formula (3)
- get molar mass of empirical formula
- divide M of molecular formula by M of empirical formula
- multiply empirical formula by result in 2.
stoichiometry (1)
ratio and relationship of reactants to get a certain product
calculate amount of an ingredient (4)
- balance equation
- get no of mol
- use ratio to get mol of substance working out
- calc mass of substance u need
molar gas volume definition (1)
volume of gas at STP
limiting reactant (1)
reactant that moles will be used up first
percentage yield (2)
percentage of physical product available compared to amount that should be formed
this is often different due to impure substances
actual yield (2)
actual amount of product formed, always diff to theoretical yield
theoretical yield (1)
amount of product that should be formed based on ratios
percentage yield formula (1)
actual yield/theoretical yield x 100
