mod 2 foundations Flashcards
isotopes
same number of protons & electrons different number of neutrons
Relative atomic mass
the weighted mean mass of an element relative to 1/12 of an atom of carbon-12
Relative isotopic mass
The mass of an atom of isotope compared with 1/12 of the mass of an atom of carbon-12
Calculate RAM
(% x mass) + (% x mass)
100
Moles
The amount of substance that contains 6.02 x 10^23 of particles same as 12g of carbon-12
avogadros constant
6.022 x 10^23
N= n x NA
Ideal gas law
PV = nRT P=pressure (pa) V=volume(m3) R=constant(8.31) T=temp (k)
properties of ideal gas law
- all particles are identical & in random continuous motion
- particles travel in straight lines
- the particles dont react when they collide
- the particles have no intermolecular forces between them
Molar gas volume
At room temp and pressure, 1 mole of gas occupies a volume of 24dm3
V= n x 24dm3
Percentage yield
actual yield / theoretical yield
x100
Atom economy
Mr of desired product / sum of all Mr of reactants
Water of crystalisation
Water molecules that form part of the crystalline structure
anhydrous-dehydrated (no water)
hydrated(water)
metallic bonding
strong electrostatic force of attraction between positively charged ions and sea of delocalised electrons
- high melting and boiling points
- good conductors (solid&liquid)
- malleable&ductile
covalent bonding
strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atom
eg-N2,CO2
Dative covalent bond
one element gives both electrons to the bond
eg-NH4