Inorganic memory parts module 2 Flashcards
Relative isotopic mass
The mass of an isotope relative to 1/12th of the mass of an atom of carbon-12
Relative atomic mass
(Ar) The weighted mean mass of an atom of an element relative to 1/112th the mass of an atom of carbon-12
Ar = total (% abundance x relative isotopic mass) / 100
Key ions
- NH4+
- OH-
- NO2-
- NO3-
- HCO3-
- Mno4-
- CO3^2-
- SO4 ^2-
- SO3^2-
- Cr2O7^2-
- PO4^3-
Empirical formula
The simplest whole number ratio or atom of each element in a compound
Relative molecular mass (Mr)
Compare the mass of a molecule with the mass of an atom of carbon-12
Assumption of hydrated salts
- all the water has been lost (reheat crystals until the mass of the residue no longer changes)
- no further decomposition
Standard solution
A solution of a known concentration
Standard solution
A solution of a known concentration
Molar gas volume
The volume per mole of gas molecules at a stated temperature and pressure
Ideal gas equation
pV = nRT
P - pressure (Pa) (kpa tp pa x10^3)
V - volume (M3) (x10^-6)
n - moles
R - ideal gas constant
T - temperature (k) (+273)
Percentage yield
= actual yield/theoretical yield
atom economy
= sum of molar mass of desired products / sum of molar mass of of all products x 100
Ionic bonding
The electrostatic attraction between a positive and negative ion.
Properties of ionic
- high melting and boiling point
- soluble in polar substances
- good electrical conductor
Covalent bonding
the strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atom.
Dative covalent bond
A covalent bond in which the shared pair of electrons has been supplied by one of the bonding atoms only
What determines shape of molecule
- electrons pairs around the central atom repel each other as far apart as possible
- greater number of electron pairs the smaller the bond angle
- lone pairs repel more strongly than bonded pairs
electronegativity
The attraction of the bonded pair of electrons in a covalent bond is electronegativity
non polar bonds
the bonded pair of electrons is shared equally between the bonded atoms
What affect the strength of intermolecular forces
- the number of electors (the more electrons the mean larger the dipoles, more energy is needed to overcome the intermolecular forces increasing boiling point)
Hydrogen bond
a type of intermolecular force found between molecules containing
- an electronegative atoms with lone pair of electrons (O,N,F)
- Hydrogen atom attached
