Exam 3 memorizations

Standard state in regards to gas, liquids, solids, and solutions

Gas: 1 atm

Liquids and Solids: 1 atm (and usually 25 C)

Solutions: 1 M

The activity of a chemical: solids, liquids, gases, solutions, at standard state

solids and liquids: activity = 1

Gases: activity = partial pressure/1 atm

Solutions: activity = concentration/ 1 M

at standard state: activity = 1

K 

equilibrium constant

Q

Reaction quotient.

formula for gibbs free energy

ΔG = ΔH - TΔS

ΔG = formation products - formation reactants

formula for Reaction Quotient (Q)

formula for equilibrium constant (K)

formula for equilibrium constant (K) when all reactants and products are in the same phase

Original formula but omit solids and liquids

Example:

Formula:

2HgO(s) + H2​O(l) + 2Cl₂(g) ⇌ 2HOCl(aq) + HgO⋅HgCl₂​(s)

Write out formula omitting (s) and (l)

K = [HOCl]² / [Cl₂]²

When K > 1

reaction favors products, equilibrium lies to the right

when K < 1

reaction favors reactants, equilibrium lies to the left

when K = apprx 1

Reaction favors neither products nor reactants, equilibrium lies in the middle

when 10^-3 < K < 10³

K contains an significant amount of reactions and products at equilibrium

K_p vs K_c

K_p 

• used for gaseous reactants and based on partial pressures

K_c

• reactions in solutions regarding Molar concentrations

K_p = (RT)^Δn

R=0.0821

R constant for Latm/molK

0.0821

R constant for J/molK

8.314