Lecture 1: Ideal gas law, chemical equilibrium

what determines the state of a gas?

pressure

volume

temperature

number of particels (n)

what is one celcius in Kelvin?

what is one Kelvin in celcius

Beispiel 25 Celcius in Kelvin

K= °C+ 273,15

°C = K - 273,15

Beispiel: Wenn Sie 25 Grad Celsius haben, beträgt die Umrechnung in Kelvin 25 + 273,15 = 298,15 K.

atm in Pa

Pa in atm

atm*101325

Pa/101325

Torr in Atm

Atm in Torr

Torr= Atm * 760

Atm = Torr/760

Ammonia

Chlorine

Hydrogen

NH3

Cl2

H2

H2S

CH4

NO2

Hydrogen sulfide

Methane

Nitrogen Dioxide

postulates of the kinetic theory of gases

• most volume is empty space

• collisions account for the pressure of the gas

• perfectly elastic =) no kinetic energy lost. Energy remains stable

• No attraction or repulsion between molecules unless collision

Standart Temperature and Pressure (IUPAC and DIN)

Standart Ambiente Temperature and Pressure

0 °C (273,15) and 10^5 Pa

Boyles law

the volume is inversely proportional to the presure

v= 1/p and vice versa

Gay-Lussac law

Avogadros law

equal volumes of any two gases at the same temperature/pressure contain the same number of particles

the molar gas volume

Vm

The volume occupied by one mole of an ideal gas

At 0 degrees = 22.4 L/mol

at 20 degrees = 24.0 L/mol

at 25 degrees = 24.8 L/mol

how do you calculate V out of Vm

V= Vm times n

Increasing the number of particles leads to increased _____ via ________

Increasing the number of particles leads to increased pressure/volume via fully elastic collisions

BOYLE'S law CHARLES' law AVOGADRO’s law short proportions

V ~ 1/p p *v = constant

V ~ p and t V/t = constant

V~ n

The Ideal Gas Law

p · V = n · R · T

molar gas constant

R = 8,3145 J/Kmol

R= 0,0820 Latm/Kmol

pressure times volume =

energy in Joule

Pa m³ = N/m² * m³ = Nm = J

Real gases

consist of atoms/molecules with intermolecular attraction/repulsion

vapour pressure

Osmosis vs diffusion

Osmosis – Osmosis is the movement of solvent particles (usually water) across a semipermeable membrane from a dilute solution to a concentrated solution. The solvent dilutes the concentrated solution until concentration is equalized on both sides of the membrane.

Diffusion – Diffusion is the movement of solvent and solute particles from an area of higher concentration to lower concentration. At equilibrium, the net effect is a homogeneous concentration throughout the medium.

what is the differnce between a saturated and an unsaturated solution?

In an unsaturated solution part of the solute remains undissolved

what is the product of sedimentation?

precipitate

when is equilibrium?

When the net change of the products and reactants is zero, the reaction has reached equilibrium

reaction rate

change in amount of substance overime

amount of products formed or reactants used

the law of mass action

K

concentration at equilibirum not starting conditions

the larger K the___

more the reaction lies on the products side

avogadros number

6.022 × 10²³

activity

Applies whenever different phases are in contact with one another:

• a solid and a liquid

• two not miscible liquids (oil/water)

• etc.

The substance in contact with the phase in question always (!) has an activity of a(substance) = 1. (no unit!)

when does saturation occur?

when IP bigger or the same as Ksp

what do we use for Ksp?

pKsp = -lgKsp

Insoluble ionic compounds

CO3²- Carbonates

PO4³- Phosphates

S²- Sulfide

OH^- Hydroxide