Physical Topics 2, 3, 4 & 6 Flashcards
Volume that one mole of any gas fills at room temperature and atmospheric pressure
24 dm^3
Empirical formula
The simplest whole number ratio of atoms of each element present in a compound
Molecular formula
The actual number of atoms of each element present in one molecule of the compound
Atom economy
The proportion of reactants that are converted into useful products rather than waste products
Percentage yield
Compares the actual amount produced compared to the maximum theoretical amount that should be produced
Apparatus error
Margin of error divided by quantity measured multiplied by 100
Must be same number of dps
Experimental error
Real answer minus experimental answer divided by real answer multiplied by 100
Electronegativity
The power/ability of an atom to attract the electron density in a covalent bond towards itself
Electron pair repulsion theory
Each pair of electrons around an atom will repel all other electron pairs
The pairs of electrons will take up positions as far apart as possible to miniseries repulsion
Standard enthalpy of combustion
The enthalpy change when one mole of substance is completely burned in oxygen under standard conditions, all species being in their standard states
Standard enthalpy of formation
The enthalpy change when one mole of substance is formed from its constituent elements under standard conditions, all species being in their standard states
Hess’ Law
The enthalpy change for a chemical reaction is the same, whatever the rouge is taken from reactants to products
Bond enthalpy
The standard enthalpy change associated with breaking one mole of covalent bonds in a gaseous substance into individual gaseous atoms
Dynamic equilibrium
Both forward and backward reactions occur at the same rate so the concentrations of all the reactants and products remain constant
Le Chatelier’s Principle
If a system at equilibrium is disturbed, the equilibrium moves in the direction that tends to reduce the disturbance
