Chem Flashcards
Hund’s Rule
Orbital’s are singularly occupied before they are doubly occupied
Pauli’s Exclusion Principle
No electrons can occupy the same Quantum state
Aufbau Principle
Electrons occupy lower energy levels before they occupy higher energy levels
Overall energy change of a system
H(products)-H(reactants)
bond energy calculations
H(reactants)-H(products)
Q=mcdeltaT
Measurement for heat capacity
m- mass in grams
c- specific heat capacity in kj per gram (decimal)
Delta T - temperature in whatever unit
Dispersion forces are greater for…
heavier or larger atoms
Dipole - dipole forces are greater for…
a greater electronegativity difference
1 gram to milligrams
1000 milligrams to a gram
Yield….
the amount of product produced from a reaction
% Yield =
ex. yield/ theoretical yield * 100
Acid + reactive metal –>
salt + hydrogen
Acid + metal hydroxide –>
salt + water
Acid + metal carbonate –>
salt + water + carbon dioxide
Vapour pressure and Intermolecular forces relationship
substances with stronger intermolecular forces have lower vapour pressure, as the molecules have less kinetic energy as they are connected more tightly than substances with weaker intermolecular forces.
e.g non-polar substances have greater vapour pressure than polar ones, because hydrogen bonding is stronger than dispersion forces
Trends in solubility
bromide, chloride, idiode, nitrate and sulfate are mostly soluble
carbonate, hydroxide, oxide and phosphate are mostly insoluble
NITRATE IS ALWAYS SOLUBLE
Silver is USUALLY insoluble, except for nitrate and sulfate (p)
Spectator ions
are the ones that don’t precipitate
m/v equals
mass/volume
All sections in a reaction must
have the same rate
Acids dissociate to produce
Bases dissociate to produce
H+
OH-
All ionic compounds are
polar and therefore all have high boiling points and low vapour pressure
Nanomaterials are
from 1-100nm long and often show different properties than larger samples of the same material
they have specialised carbon structures such as nanotubes, graphene and fullerene
Flame colours indicate the metal used
as flame colours are due to excited ions, jumping an orbital, emitting electromagnetic radiation
