mass and molar Flashcards
a standard solution
A standard solution is a solution whose concentration is accurately known.
how is a solution formed
A solution is formed when a solute completely dissolves in a solvent. the amount of solute dissolved in a solvent determines its concentration.
Molar concentration
the number of moles of solute present in 1 dm 3 of solution
unit for molar concentration
mol / dm3 or mol dm – 3
Mass concentration
the mass of solute present in 1 dm3 of solution
unit for mass concentration
g / dm3 or g dm – 3
Mass concentration =
Molar concentration X RMM
molar concentration formula
mass /rmm
molecular formula
shows the number of atoms of
each type of element present in a molecule.
empirical formula
gives the simplest ratio in which the atoms combine.
E.G.
Molecular formula: C2H6 Empirical formula: CH3
Molecular formula: C4H8 Empirical formula: CH2
how to write empirical formula
Mass present (g)
Mass of 1 mole (g)
Number of moles present
Simplest ratio
if it is 1.5 2.3 etc
multiply to get whole number
CONDITIONS NEEDED FOR AN ELECTRIC CURRENT TO FLOW-
mobile ions
present in molten ionic compounds and solutions of ionic compounds.
CONDITIONS NEEDED FOR AN ELECTRIC CURRENT TO FLOW-
mobile electrons
present in metals and graphite
POSITION OF THE ION IN THE ELECTROCHEMICAL SERIES
The electrochemical series is a list that places metals in order of their reactivity. The metals high in the series
are more reactive than those lower down. If the ions they form are considered, the ease with which they are
discharged in electrolysis can be determined. The lower the ion, the easier it is to be discharged.
