Equations Flashcards
n (mols) =
mass(g) / Mr (g mol-1)
molar volume (Vm) =
24 dm3 mol-1 at RTP
so Vm= 24 = volume in dm3/mol
concentration (mol) =
conc = mol/vol in dm3
V1 x M1/n1 (volume x molar conc / coefficient in equation) =
V2 x M2/V2
percentage uncertainty =
(uncertainty x no. measurements) / measurement made x100
percentage yield =
(actual yield / theoretical yield) x100
E⦵cell =
E⦵cell = E⦵red - E⦵oxi
or
E⦵cell = right - left
Q=
Q = mCΔT
Q= Energy (J) m= mass of water (g) C= specific heat capacity of water (4.13 J g-1 k-1) ΔT= initial - final temperature
pV=
pV=nRT
p= Pressure (Pa) V= Volume (m3) n= mols R= Gas Constant (8.31) T= Temperature (K)
ΔG =
ΔG = ΔH - ΔSsystem
ΔG = -RTlnk
ΔG is measured in kJ mol-1
Ka =
Ka = [H+] [A-] / [HA]
Ka = 10 (-pKa)
pKa =
pKa = -lg Ka
pH =
pH = -lg [H+]
when ΔG = 0 ,
when ΔG = 0
ΔH = TΔSsystem
ΔSsystem =
ΔSsystem = E(ΔS products) - E(ΔS reactants)
ΔSsystem = ΔH / T
T =
T = ΔH / ΔSsystem
ΔStotal =
ΔStotal = ΔSsystem + ΔSsurroundings
ΔS is measured in J mol−1 K−1
ΔSsurroundings =
ΔSsurroundings = -ΔH / T
when ΔStotal = 0 , then
ΔStotal = 0, then
ΔStotal ∝ lnK
0 = ΔSsystem - ΔH/T
ΔH =
ΔH = -Q/mols
ΔlatticeH =
ΔlatticeH = ΔatH [X(s)] + IE(1)[X(g)] + ΔatH [1/2 Y2(g)] + Eea(1)[Y(g)] + ΔfH[XY(s)]
ΔlatticeH = ΔhydH [X+(g)] + ΔhydH [Y-(g)] - ΔsolH[XY(s)]
bond enthalpy (ΔreactionH) =
bond enthalpy (ΔreactionH) = EΔH(bonds broken) - EΔH(bonds made)
[H+] =
[H+] = 10 (-pH)
[H+] = (Ka x [HA]) / [A-]
Kw =
Kw = [H+] [OH-]
pKw =
pKw = -lg Kw
k = (Arrhenius equation)
Ea =
A =
T =
k = Ae(-Ea / RT) where -Ea/RT is a power
Ea = -RT ln ( k/A ) not a power here
A = k / e( -Ea/RT) to the power of
T = Ea / -R ln (k/A) not a power
Kp =
Kp = (PC)c x (PD)d / (PA)a x (PB)b
Kc =
Kc = [products]b / [reactants]a
PA =
xA =
xAP =
PA = xAP xA = mols of gas A / total mols of gas xAP = xA multipled by the total pressure in atm
