Chemistry 1252 - Exam 1

Covers: Chapter 9 - Gasses & Chapter 10 - Liquids and Solids

Gas Pressure

The force exerted on a given area (P=F/A)

The relationship between pressure and temperature

Proportional ( P1/T1 = P2/T2)

The relationship between temperature \n and volume

Proportional (T1/V1 = T2/V2)

The relationship between pressure and volume

Inversely Proportional (P1 x V1 = P2 x V2)

The relationship between volume and amount (moles) of gas

Proportional ( V1/N1 = V2/N2)

What makes a gas behave ideally?

Low pressure and high temperature

Ideal Gas Law

PV=nRT

How the partial pressure of a gas in a mixture is related to the total pressure of the \n mixture.

Add all of the partial pressures together to get the total pressure of the mixture.

Mole Fraction

Number of moles of a component / Total moles

Diffusion

Prosses by which molecules disperse in space in response to differences in concentration

Effusion

The escape of a gas molecule through a tiny hole such as a pinhole in a balloon into a vacuum

How molar mass impact molecular speeds of gases.

The average speed of a molecule is inversely proportional to the square root of their masses

How temperature impact molecular speeds of gases.

The average kinetic energy of the gas molecule is proportional to temperature

The factors that make a gas behave non-ideally.

Low pressure and high temperature

Van der Waals Equation

Used on gasses that do not behave ideally

The two correction factors on the Van der Waals Equation

Molecule attraction and volume of molecules

Intermolecular Forces

Forces BETWEEN atoms/ molecules

Intramolecular Forces

Forces that hold an atom together in a molecule

Dispersion Forces

force that is present in all substances (caused by induced/ instantaneous dipoles)

Dipole-Dipole Forces

The force that is found in permanently polar molecules

Hydrogen Bonds (NOT REAL BONDS)

Forces that are found in liquids when Hydrogen is bonded to either Nitrogen, Oxygen, or Fluorine

Strength of intermolecular forces from least to greatest

Dispersion < Dipole-Dipole < Hydrogen Bonds

How polarizability impacts the strength of intermolecular forces

As polarizability increases, the IMFs also become stronger.

How polarizability impacts boiling point

As polarizability increases, so do boiling points.

How to rank polarizability of atoms/compounds

Smaller atoms are less polarizable than larger ones

Viscosity

A measure of a liquids resistance to flow

Relationship of viscosity and IMFs

Proportional, the stronger the IMFs the more viscus the liquid

Relationship of viscosity and Temperature

Inversely proportional, the higher the temperature the lower the viscosity.

How the strength of intermolecular forces impacts surface tension.

Proportional, as the stronger the IMFs the more surface temperature it has.

Vaporization

Liquid to Gas (endothermic)

Fusion

Solid to liquid (endothermic)

Sublimation

Solid to gas (endothermic)

Condensation

Gas to liquid (Exothermic)

Freezing

Liquid to solid (Exothermic)

Deposition

Gas to solid (Exothermic)

Boiling point

the temperature at which the vapor pressure of a liquid equals the external pressure surrounding the liquid.

Normal Boiling point

Boiling point when surrounding pressure is equal to 1 atm

Change in temperature equation

q= amount x Specific heat x Change in temperature

Change in temperature (phase change)

q= Amount x theta H of phase change

A

Gas

B

Liquid

C

Solid

D

Triple Point

E

Critical Point