- Boyle's Law
PV = constant [at constant n , T] ∴ P1V1 = P2V2 - Charle's Law VT= constant [at constant n , P] ∴V1T1=V2T2
Vt = Vo ( 1 + t / 273 ) [T(kelvin = 273 + t(oC)] - Gay-Lussac's Law PT= constant [at constant n , V] ∴P1T1=P2T2
- Ideal Gas Eqaution PVnT= R = 0.0821 l . atm . K-1 . mol-1
= 1.987 Cal K-1 . mol-1 = 8.314 J K-1 . mol-1
1 atm = 760 mm of Hg = 76 cm of Hg = 101325 pascal ; 1 bar = 0.9863 atm
Satnadard Temperature and Pressure (STP) or Normal Temperature and Pressure (NTP)
P = 1 atm , T = 0oC or 273 K - Density and Molar Mass Relation
Density (D) =PMRT - Dalton's law of Partial Pressure
PTotal = P1 + P2 + P3 + .....
where P1,P2,P3, .... etc are partial pressures of individual gases .
Partial Pressure = Total pressure x mole function
Relative humidity =Partial pressure of water in airVapour pressure of water
Vap. Pressure of dry gas = Vap. Pressure of wet gas - Vap. pressure of water vapour (aqu. Tension) - Graham's Law (Diffusion and Effusion)(rA) Rate of effusion of gas A(rB) Rate of effusion of gas B=√ρB√ρA=√MB√MA[at constant pressure](rA) Rate of effusion of gas A(rB) Rate of effusion of gas B=PAPB√ρB√ρA=PAPB√MB√MA[at different pressure]
- Velocity of Molecules
- Real Gases , compressibility Factor
Z =PVnRT
Z measures the extent of non - idealness of an ideal gas .
Z < 1 , implies that gas is more compressible
Z > 1 , implies that gas is less compressible
Z = 1 , implies that gas is ideal - Gas Equation (van der Waal's)
- Nature of Gas Constant R
R =PVnT=Pressure x VolumeMoles x Degree(K)=(Force / Area) x VolumeMoles x Degree(K)=Force x LengthMoles x Degree(K)= Work Done per degree per mole - Units of Gas constant (R)
R = 0.0821 atm L K-1 mol-1 = 0.0821 atm dm3 K-1 mol-1
(Here P = 1atm , V = 22.4 L , T = 273K , 1 L = 1 dm-1)
If P is expressed in dynes per square centimeter (P = 76 x 981 x 13.6 dyne/cm2)
V = 22400 dm3 and T = 273 K
then R = 8.314 x 107 ergs K-1 mol-1 = 8.314 JK-1 mol-1 and R = 1.987 cal K-1 mol-1
1 atm pressure = 0.76 m x 13.6 x 103 kg m-3 x9.81 ms-2 = 101.325 x 103 Nm-2 = 101.325 x 103 Pa
1 Nm-2 = 1 Pa
Thus , the gas constant R =(101.325 x 103 Nm-2) x (22400 x 10-6m3)(273K) x (1 mol)= 8.314 x NmK-1 mol-1 = 5.189 x 1019 eVK-1 mol -1
[ 1eV = 1.602 x 10-19 volts coulomb (Joule) ] - Avogadro's Law
V α n or V α N (at constant T,P) - Calculation of Kinectic Energy
Acoording to gas equation , Pv =13Mu2 for 1 mole of gas
or PV =2312Mu2 for 1 mole of gas
K.E. =12=32PV =32RT
For molecule , the KE =32RTNo=32KT
K(Boltzman constant) =RNo - Average molecular weight of a gaseous mixture
Mmix =Σ niMiΣ ni, where ni is the number of moles and Mi is the molecular weight of the component. - Critical Pressure (PC) = a27b2
- Critical Temperature (TC) = 8a27Rb
- Critical Volume (VC) = 3b
- Relation between PC , VC and TC : PCVCRTC=38
- Boyle's Temperature (TB) = abR
Sunday, March 30, 2014
STATES OF MATTER
REDOX REACTIONS AND ELECTROCHEMISTRY
- Ecell = Eocell - log[Products][Reactant]
- Δ G = nFEcell ; - Δ Go = nFEocell
Eocell =2.303 RTn Flog Keq =0.591nlog Keq [at 250C]
Δ Go = - 2.303 RT logK - Gibb's Helmholtz Equation
- Faraday's First Law
w = Z i t , 1 faraday is the quantity of charge carried by 1 mole of electrons.
Z =equivalent mass96500; Z = weight deposited when 1A passed for 1 sec. - Faraday's second Lawm1m2=E1E2
m1 , m2 are masses deposited and E1 and E2 are their equivalent weights ; for same amount of passed charge .
%current efficieny =Actual CurrentAmmeter currentx 100
Ohm's Law = I = E/R
Ions are always discharged / produced in equivalent amounts whatever their speeds of deposition are ,
Specific conductance = κ = 1 / ρ , ρ = specific resistance
ρ =lax Cla= constant , C = conductance =1R
Conductivity = cell constant x observed conductance
πeq =kCeq=K x 1000 cm3 L-1Normality - Equivalent conductance , (Λ)
Λ = κ x V
V = volume in mL containing 1g equivalent of the electrolyte.
Molar conductance (μ) = [Equivalent conductance]
(μ) = nΛ
n =Molecular MassEquivalent Mass
μ = κ x V V(mL) containing 1g mole of an electrolyte.
At infinite dilution , Λo = λa + λc
λc = kuc
λa = kua
λa and λc , ionic conductance of anion and cation
k = 96500C
ua = mobility of anion
ua = mobility of cations
degree of dissociation = Λ / Λ∞
α = ( K / C)1/2 =λeCλe∞=λmCλμ∞
λeC , λmC = equivalent and molar conductance - Ostwald's Equation
K =C( λmC )2λm∞ (λm∞ - λmC) - Cell Notation
Transport Number
Transport Number =Current carried by ionToatl current carried
nc + na = 1
ATOMIC STRUCTURE
- Planck's Quantum Theory
E = hν =hcλ
where h = Planck's Constant (6.023 x 10-34 Js) , ν = Frequency of radiation , c = Velocity of Light , λ = Wavelength of radiation
c = νλ and wave number =1λ - Moseley's Equation
√ν = a (z - b) - Heisenberg's uncertainity Equation
Δp . Δx ≥h4πand ΔE . Δt ≥h4π
Kinetic Energy of electron in the nth quantum state =12Zke2rn
Potential Energy of electron in the nth quantum state = -Zke2rn
Total energy (E) = -Zke22rn= -(13.6)Z2n2eV per atom
= -313.6n2kcal / mol = -1312n2kJ / mol
= - 21.8 x 10-19Z2n2J / atom - Radius of nth quantum state = n2h24π2mkZe2=n2aoZ(ao = 0.529 A)
- Velocity of electron (vn) = 2ρZke2nh=Znx 2.188 x 106 m/s
No. of revolutions per second in r.p.s. =vn2πrn=Zvn2πn2ao
Wave number of spectral line , - de Broglie Equation
Azimuthal (or angular) Quantum number (l) ; 0 ≤ l ≤ n - 1
Orbital angular momentum , L = √l ( l + 1 )h2π
Magnetic quantum number (m); - l ≤ m ≤ l , total (2l + 1)
Magnetic Moment , μL =eh4πmc√l ( l + 1 )
Spin angular momentum = √s( s + 1 )h2π - Aufbau Principle
Subshell qith lowest (n + l) , value is filled first , if two subshells have same (n + l) value , lower value of 'n' is filled up first . - Photoelectric Effect
Maximum kinectic energy of ejected electron12mv2max = hν - hνo
Stopping Potential , eV = hν - hνo
Binding Energy = Mass Effect x 931 MeV- Radius of Nucleus (rn) = ro x A1/3 , where A is the mass number and ro is proportionality constant whose value is 1.4 x 10-13 cm
- Although energy of electron increases with the increase in the value of n (orbit) , yet the difference of energy between successive orbits decreases .
Thus , E2 - E1 > E3 - E2 > E4 - E3 > E5 - E4....etc. - No. of spectral lines when electron comes from nth level to ground level = n (n + 1)/2
- No. of sub-shells in a main energy level = n
- No. of orbitals in a main energy level = n2
- No .of orbitals in a sub shell = (2l+1)
- No. of electron in each orbit = 2
- Maximum no. of electron in a sub shell = 2 (2l+1)
- Maximum no. of electron in a main shell = 2n2
CHEMICAL AND IONIC EQUILIBRIUM
- Equilibrium in Water :
- Equilibrium Constant , K = [C]c[D]d[A]a[B]b=kforwardkbackward= KC
- In terms of partial pressure
Equilibrium Constant , Kp =pCc pDdpAa pBb= Kc (RT)Δng [Δng = np - nr]
- Equilibrium Constant , K =
- Van't Hoff Equation :
- Gibb's Free Energy
ΔG = Δ - TΔS
ΔGo = - 2.303 RT log10K - Buffer :
pH = pKa + log[conjugate base][acid]
pOH = pKb + log[conjugate acid][base]
Mixture of weak acids = ( k1c1 +k2c2 )1/2
α =% conjugation100
∴ Ksp = [Ay+] x [Bx-] y - Arrhenius Concept :
Substance which give H+ ions when dissolved in water are called acids , while gives OH- ions are called bases. - Bronsted Lowry Concept :
Acid donates proton , base accepts ptoton. - Ostwald's Dilution Law :
α = ( K / C)1/2
K = dissociation constant of weak electrolyte
C = Concerntatation
α = degree of dissociation
KW = [H+ ][OH- ] - Hydrolysis Constant :
Kh =h2C1 - h
h =amount of salt hydrolysedTotal salt taken
THERMODYNAMICS
- Mechanical Work
W = - Pext (ΔV) [during expansion] - First Law of Thermodynamics
ΔE = q + W
ΔE = q - PΔV - Adiabatic Change
- Isochoric Change
ΔV = 0
W = PΔV = 0
ΔE = q + W = q - Cyclic Change (reversible)
ΔE = 0
q = -W = PΔV
q = -Wmax = P∫dV - Isothermal reversible Expansion
ΔH = ΔE = 0 (internal energy is a function of temperature)
q = -Wmax = 2.303 nRT log( V2 / V1) = 2.303 nRT log( P1 / P2)
ΔH = ΔE + ΔngRT - Joule - Thompson coefficient
(i) For cooling , u > 0 (-ve sign)
(ii)For heating , u < 0 (+ve sign) - Second Law of Thermodynamics
Efficiency of the Carnot engine = η =q2 - q1q2=T2 - T1T2= 1 -T1T2
q2 = heat absorbed by engine
q1 = heat lost to sink - Entropy Change
ΔStotal = ΔSsystem + ΔSsurrounding
ΔSfusion =ΔHfusionTfusion; ΔSvapour =ΔHvapourTvapour - Gibb's Free Energy (G)
ΔG = G2 - G1
ΔG = ΔH - TΔS (Gibb's Helmholtz equation)
ΔG < 0 (means spontaneous process)
ΔG > 0 (means non-spontaneous process)
ΔG = 0 (means system is at equilibrium) - Kirchoff's EquationΔH2 - ΔH1T2 - T1= ΔCp andΔE2 - ΔE1T2 - T1= ΔCv
where , ΔCp = ∑Cp(products) - ∑Cp(reactants) and ΔCv = ∑Cv(products) - ∑Cv(reactants) - Degree of Dissociation (x)
x =D - dd=Mt - MoMo
where , D = theoretical V.D. and d = observed V.D. - pH of a solution
pH = -log[H3O+]
pOH = -log[OH-]
pH + pOH = pKW = 14 - Isothermal (reversible)
ΔS = 2.303 nR log (V2 / V1)
at constant pressure ,
ΔS = 2.303 Cp log10 (T2 / T1)
For vaporization ,
ΔS =ΔHvapTbp
ΔGo = - nFE0cell - Sign Convention
- If work is done on the system , W is +ve.
- If work is done by the system , W is -ve.
- If heat is absorbed by the system , or ΔH is +ve.
- If heat is given out by the system , q or ΔH is -ve.
- If energy is absorbed by the system , i.e. internal energy increases , ΔE is +ve.
- If energy is released i.e., internal energy of the system decreases , ΔE is -ve.
- Heat Capacity
(i) Heat capacity at constant volume , CV = [ ∂E / ∂T ]V
(ii) Heat capacity at constant pressure , Cp = [ ∂H / ∂T ]p
For an ideal gas , Cp - Cv = R - Heat of Reaction
ΔH = ∑ H(p) - ∑ H(R)
For exothermic reaction : ∑ H(p) < ∑ H(R) (∴ Δ is -ve)
For endothermic reaction : ∑ H(p) > ∑ H(R) (∴ Δ is +ve)
Heat change at constant pressure = qp = ΔH
Heat change at constant volume = qv = ΔH
ΔH = ΔU + PΔV
ΔH = ΔU + Δn(g)RT
If,
Δn(g) = 0 , ΔH = ΔU
Δn(g) > 0 , ΔH > ΔU
Δn(g) < 0 , ΔH < ΔU - Clausis - Clapeyron Equation
where ΔHv = molar heat of vapourisation- Calorific Value is the amount of heat evolved when one gram of fuel as food is burnt in the presence of air or excess of oxygen.
- Joule's Relationship between work done (w) and heat produced (H)
W α H or W = JH
where J = mechanical equivalent of heat ; J = 4.184 JCal-1 - S1 and S2 are solubility at temperature T1 and T2 respectively
SOLUTIONS
- Solubility
ΔHsolution = ΔHlattice - ΔHhydration
If hydration energy > lattice energy , the solute goes into solution and ΔHsolution comes out to be -ve value i.e., the process is exothermic. - Henry's Law
Mass of the gas dissolved per unit volume (n) α pressure (P) - Parts per million
ppm (A) =Mass of ATotal mass of the solutionx 106
Weigth % = wt. of solute per 100gm of solution
Volume % = wt. of solute per 100ml Of solution or Volume of solute per 100ml of solution
Mole % =Mass of soluteMoles of solute + Moles of solventx 100 - Relationship between Molality(m) of a solution and Mole fraction of the solute (X2)
X2 =m M11 + m M1, where M1 is the molecular mass of the solvent - Relationship between Molality(m) , Molarity (M) and Density of a solution (d)
Molality , m =M1000d - MM2x 1000 , where M2 is the molar mass of the solute . - Relationship between Mole fraction of the solute (x2) and Molarity (M) of the solution
X2 =MM1M(M1 - M2) + d
where M1 & M2 are the molecular masses of solvent and solute respectively . Density of solution is d. For isotonic or iso-osmotic solutions . - Raoult's Law (Vapour - Pressure lowering of solution)
ps = po.Xsolventpo - psps=nN
po = pressure of pure solvent ; ps = pressure of solvent
α , during dissociation ,
α =i - 1n - 1, n = no. of ions after dissociation
α , during association ,
α =1 - i1 - (1/n)
Variation of vapour pressure with temperature
Variation of vapour pressure with external pressure - Osmotic Pressure
π = iniVRT = hdg (due to association or dissociation) - Van't Hoff Factor
i =PobservedPnormal=(Δp)observed(Δp)normal=(ΔTb)observed(ΔTb)normal=(ΔTf)observed(ΔTf)normal=Normal molecular massObserved molecular mass
For solution showing dissociation , the Van't Hoff factor i > 1
For solution showing association , the Van't Hoff factor i < 1
For solution showing no dissociation or association, the Van't Hoff factor i = 1 - Raoult's Law
P = PA + PB = PA0 XA + PB0 XB = ( 1 - X )PA0 + PB0 XB - Ideal Solutions
They obey Raoult's law for all range of concerntatation and temperature. ΔHmix = 0 and ΔVmix = 0
eg. Hexane + Heptane ; Ethyl bromide + Ethyl chlroride ; Chlorobenzene + Bromobenzene , etc.. - Non - Ideal Solutions
The non-ideal solution do not obey Raoult's law for all concerntatation.
ΔHmix ≠ 0 and ΔVmix ≠ 0
If ΔHmix > 0 and ΔVmix > 0 , then non-ideal solutions show +ve deviations.
If ΔHmix < 0 and ΔVmix < 0 , then non-ideal solutions show +ve deviations.
e.g. Acetone + ethyl alcohol , water + ethyl alcohol , CCl4 + CHCl3 , etc. - Types of Azeotropic Mixtures
(i) Minimum Boiling Azeotropic
eg:- Ethanol (95.5%) + water(4.5%) mixture boiling .
(ii) Maximum Boiling Azeotropic
eg:- HNO3 (68%) + water(32%) mixture boiling at 393.5K . - Elevation in boiling Point
ΔTb = Tb - To = Kb m =KB x WB x 1000MB x WA
WA = mass of solvent (g) ; WB = mass of solute (g) - Molal depression Constant (Kf)
Kf =RTf21000Lf[Lf = latent heat of fusion]
Note :- Above equation are valid only when Kf and Kb are expressed in Kelvin m-1
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