Exam 2 review: Ag + (aq) + Cl - (aq) > AgCl(s)  H = kJ Calculate  H for the formation of 2.5 g of AgCl MW g/mol (AgCl). 2.5 g/ g/mol = mole mol(-65.5 kJ/mol AgCl) = kJ –Calorimetry problem: example problem: 10 g of NaOH is dissolved in 100 mL of water in a calorimeter, the temperature changes from 23.6 to 47.4 °C. Calculate  H for the process, assume the specific heat of the solution is j/°Kg, the same as water.

Chapter 5 q = specific heat(g solution)(  T) q = 4.184j/Kmol(110 g)( ) = J moles NaOH = 10g/40 g =.25 mole  H = J/.25 mol = = J/mol NaOH. –Hess’s law: Given a series of reactions, rearrange to find  H for the reaction in question: Example problem: Given the data: N 2 (g) + O 2 (g) ----> 2NO(g)  H =180.7 kJ 2NO(g) + O 2 (g) -----> 2NO 2  H = kJ 2N 2 O(g) -----> 2N 2 (g) + O 2 (g)  H = kJ Calculate: N 2 O(g) +NO 2 (g) -----> O 2 (g) –Enthalpies of formation (the tables of enthalpies of formation): –  H prdts -  H reactants =  H reaction

Chapter 5 –Hess’s law: Given a series of reactions, rearrange to find  H for the reaction in question: Example problem: Given the data: N 2 (g) + O 2 (g) ----> 2NO(g)  H =180.7 kJ 2NO(g) + O 2 (g) -----> 2NO 2  H = kJ 2N 2 O(g) -----> 2N 2 (g) + O 2 (g)  H = kJ Calculate: N 2 O(g) +NO 2 (g) -----> 3NO(g) NO NO(g) + 1/2O 2 (g) 113.1/2 N 2 O(g) -----> N 2 (g) + 1/2O 2 (g)  H = /2 kJ N 2 (g) + O 2 (g) ----> 2NO(g)  H =180.7 kJ N 2 O(g) +NO 2 (g) -----> 3NO(g)  H =155.6 kJ

Chapter 5 –Enthalpies of formation (the tables of enthalpies of formation): –  H prdts -  H reactants =  H reaction

Chapter 6 –Characteristics of waves (v = ): What is wavelength? What is frequency? –Electromagnetic radiation: E = h visible spectrum (ROYGBV) rest of spectrum

Chapter 6 –Characteristics of waves (v = ): –Black body radiation –Photo-electric effect –Heisenberg uncertainty: (  mv  x ≥ h) –Line spectra of atoms –matter waves (De Brogli)

Chapter 6 –Wavefunctions and quantum mechanics wavefunction vs. probability distribution orbitals and quantum numbers –Quantum numbers what are the four? –principle (energy) n = 1,2,3... –azimuthal (shape) l = 0,1, 2... n-1 –magnetic (orientation) m l = -l,...0,...+l –spin (differentiates two electrons in same orbital) (±1/2) naming the l qm: l=0, s, l=1, p, l=2, d, l=3, f –Shapes of orbitals

Chapter 6 –Many electron atoms –Energy of orbitals in H versus other atoms with other electrons.

Chapter 6 –Pauli exclusion principle –Hund’s rule (don’t pair until you have to) –Electron configurations