Presentation on theme: "Learning Targets: 5.1 I can describe the principles of Kinetic Molecular Theory I can describe what atmospheric pressure is I can describe how temperature."— Presentation transcript:
Learning Targets: 5.1 I can describe the principles of Kinetic Molecular Theory I can describe what atmospheric pressure is I can describe how temperature related to motion Explain the difference between solids, liquids, and gases at the molecular level. I can interpret phase diagrams and describe the factors that affect changes of state 5.2 I can apply the Gas Laws to solve a given problem I can convert between units of measurement for pressure and temperature Apply the Gas Laws to solve a given problem Identify the 4 variables that influence gases, and explain the relationships between: Pressure and Volume Pressure and Temperature Volume and Temperature Solve problems (including stoichiometry problems) using the Ideal Gas Law 5.3 I am able to demonstrate the principles of thermochemistry Explain the relationship between energy & heat Calculate changes in heat & energy in chemical & physical processes Calculate heat & energy changes in phase changes. I can define heat within a system, specific heat, and heat capacity.
5.1: I can describe the principles of Kinetic Molecular Theory Explain the difference between solids, liquids, and gases at the molecular level. I can describe how temperature related to motion I can describe what atmospheric pressure is I can interpret phase diagrams and describe the factors that affect changes of state
Solids: Very low Kinetic Energy (KE) - particles are vibrating, but cant move around Have a fixed shape, fixed volume Liquids: Have variable shape, but fixed volume Low KE- particles can move around, but still stay very close together Variable shape, variable volume High KE- particles can move away from each other and take the shape of their container.
Kinetic Energy and States of Matter Solid - very low kinetic energy (KE) Liquid - low KE, particles can move around Gas - high KE, particles move freely & randomly
Temperature – representation of Kinetic Energy Pressure – The collisions acting against molecules Volume- the space available for molecules to move in N- the Number of molecules.
Temperature is really the measurement of Kinetic Energy of the particles involved. Kinetic Energy is due to the mass & the speed of the particles. High temperature means that particles are moving at higher speeds. Kelvin is the unit that we use to measure Kinetic Energy
Scales of Temperature Celsius vs. Fahrenheit 0 °C = 32 °F 100 °C = 212 °F
Scales of Temperature William Thompson a.k.a. Lord Kelvin Absolute temperature scale Kelvin (K) At 0 K all motion stops time stops
Scales of Temperature
Pressure is the amount of force an object puts upon a defined area In the case of gases, the Pressure can be described as the collisions of the individual gas particles on the sides of the container. KEY UNITS AT SEA LEVEL kPa (kilopascal) 1 atm (atmosphere) 760 mm Hg 760 torr 14.7 psi
Atmospheric Pressure At sea level 1 atm = lb/in 2 = KPa (kilopascals) = 760 mm Hg = 760 torr (antiquated measure) = 1, mbar (stupid US unit) = bar
Atmospheric Pressure Atmospheric pressure decreases rapidly with height. Climbing to an altitude of only 5.5 km where the pressure is 500 mb, would put you above one-half of the atmospheres molecules.
Phase Diagrams H2OH2O 218
Phase Diagrams Triple point - where the (s), (l), and (g) co-exist Critical point - where phase boundaries cease to exist * A supercritical fluid is any substance at a temperature and pressure above its critical point. It can diffuse through solids like a gas, and dissolve materials like a liquid. Supercritical fluids are suitable as a substitute for organic solvents in a range of industrial and laboratory processes. Carbon dioxide and water are the most commonly used supercritical fluids, being used for decaffeination and power generation respectively
Kinetic Molecular Theory (KMT) Kinetic energy derived from motion KMT has three main tenets: 1.Random motion - no attractive or repulsive forces between particles 2.Newtonian Motion 3.All collisions are perfectly elastic
Kinetic Molecular Theory (KMT) Newtons Laws of Motion I.An object remains at rest/motion until an outside force acts upon it II.F = ma III.To every action there is an equal and opposite reaction