Chem unit 3 exam (chapters 5 and 6) - EQUATIONS

Heat Capacity

C = heat (q)/(Final temp - Initial temp)

Specific heat capacity

q = m x C_s x (Tf - Ti)

Molar heat capactiy

q= n x Cm x (Tf - Ti)

Change in energy content

“delta” E/U = q + w

Internal energy

U = Kintetic E + Potential E

Pressure-volume work

w= -P_ext x “delta”V

Enthalpy

H = E + PV

Enthalpy change of a reaction - using enthalpy of formation

“Delta”Hº = Sum of coefficients of products x “delta”H_fº - Sum of coefficients of reactants x “delta”H_fº

Calorimeter (coffee cup)

q surroundings + q system = 0

Simple calorimeter - heat of Solution

q = m x C_s x (Tf - Ti)

Simple calorimeter - Heat of system (units are kj/mol)

q_{rxn =} “delta H'“_rxn x moles

Simple calorimeter - Heat of system (units are kj/g)

q_{rxn =} “delta H'“_rxn x mass

Frequency, wave length, and speed of light equation

$c = \lambda \, f$,

Plank’s equation

$E = h \times f$ (joules/photon)

Minimum energy needed to eject an electron

E = h x v₀

Energy values of energy levels (n)

E_n= - Rhc/n²

Energy of transition

“delta E” = -2.18×10^-18J x (1/n_f²- 1/n_i²), where n_f and n_i are the final and initial energy levels.

number of orbitals in a subshell

2l + 1

number of nodes

n -1