Table 5.3 Enthalpies of formation

Diamond is less stable than graphite. The standard heat of formation of carbon in its diamond form is +1.897kj/mol and in its graphite form is 0kj/mol

The law of summation of heats of formation states that the enthalpy of a reaction is equal to the total formation of energy of the products minus that of the reactants

***deltaH= (sigma)(n)deltaH(products)-(sigma)(m)deltaH(reactants)

Sample: Large quantities of ammonia are used to prepare nitric oxide according to the following equation: 4NH3(g)+5O2(g)4NO(g)+6H2O(g)

Delta H= (4(90.3)+6(-241.8))kj-(4(-45.9)+5(0))kj = -906kj

The standard state for carbon is graphite..most stable form of carbon at standard temp and pressure

H2O(l)H2O(g) in kj

Products-reactants… -241.8-(-285.8)=44kj

**Read about fuels**

Demo-THERMITE(turning rust to iron)

Fe2O3(s)+2Al(s)2Fe(s)+Al2O3(s) delaH=-851.5kj

Ch6

Electronic structure of atoms

Absorption and emission of light by atoms provides key evidence, light is also considered

Light is an enigma, possessing properties of both waves and particles

Planks equations for the energy of light E=hv………...energy of a light particle(photon) is equal to the frequency of light wave and (h)a constant h=6.63*10^-34 j*s

Wavelength(lambda)-ditsance between identical points in a wave…

Frequency(v, the greek letter nu) is the number of wavelengths that pass a certain point in one second.

C(speed of light)=lambda(nu)

Langer wavelength corresponds to lower frequency(and lower energy)

Speed of light is a constant that has been measured

C=3.00*10^8m/s

Fundamental constant of the universe, nothing can travel faster than light

Light is quantized, in that it comes in photons

No quantity if light less than a photon is possible

Quantized Non quantized

Piano Violin

Stair Steps Ramp

Typewriter Pencil and paper

Dollar Bills Ecxhange rates

Game score Long jump distance

Light switch dimmer switch

Matter

Energy thermal energy

Dispersion of light by a prism

ROYGBIV

Non quantized

Flames of lithiumget individual lines instead of full color spectrum (red) line spectrum, discreet wavelengths

Bohr Theory of Hydrogen Atom

(1/Lambda) =1.097x10^7m^-1(1/2^2)

Bohrs postulates

1.energy level postulate-an electron can only have specific energy levels in an atom (electron energy is quantized)

2. Transition between energy levels- an electron in an atom