Chapter 6

Question 1

Types of System

Answer 1

Isolated - no heat or matter exchange

Ex: insulated bomb reactor

Closed - Heat exchange but no matter exchange

Ex: Steam radiator

Open - Heat and matter exchange

Ex: pot of boiling water

Question 2

Types of Process System under goes

Answer 2

Isothermal - Temperature of system remains constant

Adiabatic - No heat exchange occurs

Isobaric - Pressure of system remains constant

Question 3

Calories to Joules

Answer 3

1 cal = 4.184 J

Question 4

Constant-Volume Calorimetry

Answer 4

q = mcΔT

q_rxn = -(q_water + q_bomb)

Question 5

State Functions

Answer 5

Independent of pathway

Pressure, Temperature, Volume

Enthalpy, Entropy, Free Energy and Internal Energy

Question 6

Standard Conditions (SC)

Standard State

Answer 6

25^oC and 1 atm

Substance most stable state at SC

Question 7

Enthalpy

Answer 7

ΔH_rxn = H_products - H_reactants

Question 8

Standard Heat of formation

Answer 8

ΔH^o_f

Enthalpy change of 1 mole of compound if it were formed by their standard states

Question 9

Standard Heat of Reaction

Hess’s Law

Answer 9

ΔH^o_f = (sum of ΔH^o_f products) - (sum of ΔH^o_f reactions)

Enthalpies of reactions are additive

Question 10

Bond Dissociation Energy

Answer 10

ΔH_rxn = (ΔH of bonds broken) - (ΔH of bonds formed)

= total energy input - total energy released

Question 11

Entropy

Answer 11

ΔS = S_final - S_inital

ΔS = q_rev/T

q_rev = heat added in a reversible process

T = Kelvins

Question 12

Standard Enropy Change

Answer 12

ΔS^o_rxn = (sum of ΔS^o_products) - (sum of ΔS^o_reactants)

Question 13

Gibbs Free Energy

Answer 13

ΔG = ΔH - TΔS

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• ΔG = spontaneous

ΔG = not spontaneous

ΔG = 0 at equilibrium

Question 14

Reaction Quotient

Answer 14

ΔG^o = -RT ln K_eq

ΔG = ΔG^o + RTlnQ

Question 15

ΔH and ΔS

Answer 15