Warm-up Kinetic Molecular Theory: A theory used to explain the motion and closeness of particles to one another; idea that particles of matter are always in motion. Use this definition to describe the three states of matter (solid, liquid, and gas)

Warm-up 1 Answer

KMT applies to each state of matter— –Particles of matter are always in motion Particles in solids will vibrate basically in place rather than having free(-er) movement like in a liquid or a gas –Defined/undefined shape and volume contributes to how close the particles are Restricts how close particles are to one another 3 things that affect states of matter: –Volume, pressure, temperature –Absolute temperature scale = Kelvin –0 K = absolute zero = °C The temperature at which a particle stops moving

Warm-up 2 – Phase Changes 1. Define the terms Endothermic and Exothermic. 2. Which phase changes are associated with each term and why?

Warm-up 2 Answers Endothermic—absorption of heat –Vaporization –Melting –Sublimation Exothermic—release of heat –Condensation –Freezing –Deposition ***You might want to write down all these terms to define later on!***

Warm-up 3 What are the two variables shown we can manipulate to change states of matter? Define Triple Point

Warm-up 3 Answer Pressure and Temperature –Manipulating these two variables can affect melting points, boiling points, etc. –STP—Standard Temperature and Pressure “normal” boiling/melting points are based off of standard pressure (1 atm) Triple Point –The temperature and pressure at which all three states of matter are in equilibrium Future Definitions— –Critical temperature and critical pressure

Warm-up 3 Answer Critical Point –Indicates the critical temperature and critical pressure of a substance Critical Temperature (t c ) –The temp. above which the substance canNOT exist in the liquid state Critical Pressure (P c ) –The lowest pressure at which a substance can exist as a liquid at the critical temperature (t c )

Warm-up 4 Phase Diagram for O 2 1. If the pressure increases from 0.5 to 1.5 atmospheres at a constant temperature of 50° C, which of the processes occurs? (A) Sublimation (B) Condensation (C) Fusion (D) Freezing 2. At a temperature of 70 ° C and a pressure of 1.5 atm, what state of matter would O 2 be in? 3. At 60 ° C and 1.0 atm, what can you manipulate to change the O 2 from a liquid to a gas? Solid Liquid Gas

Warm-up 4 Phase Diagram for O 2 1. If the pressure increases from 0.5 to 1.5 atmospheres at a constant temperature of 50° C, which of the processes occurs? (A) Sublimation (B) Condensation (C) Fusion (D) Freezing 2. At a temperature of 70 ° C and a pressure of 1.5 atm, what state of matter would O 2 be in? 3. At 60 ° C and 1.0 atm, what can you manipulate to change the O 2 from a liquid to a gas? Solid Liquid Gas

Warm-up 4 Answer 1) B—Condensation –As the pressure increases, the phase changes from gas to liquid 2) Liquid 3) Manipulations possible: –Reduce pressure and maintain 60°C –Increase temperature and maintain 1.0 atm –Reduce both pressure and increase temperature Phase Diagram for O 2 Solid Liquid Gas

Warm-up 5 Intermolecular forces: –Dipole-dipole Permanent, attraction between oppositely charged regions of polar molecules, stronger –London Dispersion Very weak, temporary dipole formations as electrons move, can occur between non-polar compounds –Hydrogen Bonds Strongest, occurs between hydrogen and an extremely electronegative element with at least one lone-pair of electrons How might intermolecular forces affect boiling points, vaporization points, and state of matter?

Warm-up 5 Answer The stronger the IMF between molecules, the more energy required to break those bonds. –More energy = more heat = increase temp –More energy  higher boiling, melting, etc. points Stronger IMF will keep a compound in a solid or liquid state when other compounds of comparable mass and properties will be gases –To change states of matter, energy is used to overcome the IMF between molecules and allow greater freedom of movement