Useful information for Final Exam

Strong acids: HNO3, H2SO4, HCl, HBr, HI, HClO4, HClO3

All other acids appearing on this exam are weak.

Strong bases (soluble hydroxides): LiOH, NaOH, KOH, Ca(OH)2

Names of selected polyatomic ions:

Sulfate SO42- Phosphate PO43-

Carbonate CO32- Nitrate NO3-

Ammonium NH4+ Hydroxide OH-

Conversions:

1 mL = 1 cm3

1 gallon=3.785 Liter

1 pound(lb) = 454 g

760 torr = 1 atm

T(in K) = T(in °C) + 273

Energy conversions:

1 calorie = 4.184 J

1 electron-volt (eV) = 1.6022∙10-19 J

1 Joule (J) = 6.0221∙10-19 kJ/mol

Constants and equations:

Avogadro’s number: 6.0221·1023/mol;

There are 6.0221•1023 particles in 1 mole of any substance

Electromagnetic radiation:

l = wavelength; n = frequency; Ep = photon energy

c = speed of light = 2.9979·108 m/s

h = Planck constant = 6.6261·10-34 J·s

hc=1.9865·10-25 J·m

ln = c; Ep = hn; Ep = hc/l; l = hc/ Ep

Energy and thermodynamics:

Hydrogen atom energies E=-(2.18x10-18J)/n2

Kinetic energy of particle: Ek = (1/2)mv2 (m=mass; v=velocity)

In SI units, m must be in kg (not grams or grams per mole) and v in meters/sec (m/s). The answer will be in Joules. Reminder: In kg the mass of an atom or molecule is a very small number; you need to divide the molar mass by Avogadro’s number.

E = internal energy; q = heat; w = work

1st Law of Thermodynamics: DE = q + w

Work done by the system is –

Work done on the system is +

Heat absorbed by the system (endothermic) is +

Heat given off by system (exothermic) is –

For a temp change DT, q=C∙DT (C=heat capacity)

q= m∙c∙DT (m=mass; s =specific heat)

Thermochemistry and Hess’s Law:

H = enthalpy; DH = heat at constant P;

DHf° = enthalpy of formation

(for making 1 mole of substance from elements)

Reaction DH=DHf° (products)- DHf° (reactants)

(use tabulated data and multiply by reaction coefficients)

Gas Laws:

P = pressure; V = volume; T = absolute T

n = number of moles; R = gas constant

Boyle’s Law: PV=constant (at constant T, n)

Charles’ Law: V/T=constant (at constant P, n)

Universal Gas Law: PV=nRT; R=0.08206 (L∙atm)/(K∙mol)

Note: To use this value of R, express P in atm, V in L, T in K (absolute)

Common unit conversions:

Other forms of gas law:

P=nRT/V; V=nRT/P; n=PV/(RT); T=PV/(nR)