Physical Chemistry Flashcards
Rate equation
Rate=k[A][B]
ONLY REACTANTS
Units of rate
Moldm^-1s^-1
Shapes from conc time graphs and orders
Zero-straight line -ve grad
First- downward curve decreasing grad
Second-steeper that first
Identifying first
First order have continuous half life
K from half life
K=ln2/half life
Rate concentration graph shapes
0= horizontal line constant rate
1= straight line through origin
2=upward curve
Finding k of a second order reactant
Plot rate against conc squared. K=gradient
Rate determining step
Slowest step in a reaction
Rate equation and rate determining step
Only include species in rds
Arrhenius equation
K=A. e^(-Ea/RT) A=frequency of successful collisions Ea= activation energy R=8.314 T=temp K
Mole fraction
Number of moles of A/ total moles of gas in mixture
Partial pressure
Mole fraction/total pressure
Kp
Kc but with partial pressures
What causes Kc to change?
Only temperature
Bronsted lowry acids and bases
Acid=proton donor
Base=proton acceptor
pH
-log[H+]
[H+]
10^-pH
Logarithmic scale of pH meter
pH of 1 has 10x conc of H+ that pH2
Lattice enthalpy
The enthalpy Change that accompanies the formation of one mole of an ionic compound from its gassiest ions understand it conditions
Enthalpy change of atomisation
The entropy change that takes place for the formation of one mole of gassiest atoms from the element in its standard state understand it conditions
First electron affinity
The enthalpy change that takes place when one electron is added to each atom in one mole of gassiest atoms to form one mole of gassiest one minus ions
Enthalpy change of solution
The enthalpy change that takes place when one mole of the solute dissolves in a solvent if the solvent is water the ions from the ionic lattice finish up surrounded with water molecules as aqueous ions
Enthalpy change of hydration
The enthalpy change that accompanies the dissolving of gases ions in water to form one mole of aqueous ions
Standard entropy
The entropy of one mole of substance under standard conditions
