Presentation on theme: "Ch. 16 - Solids, Liquids, & Gases I. States of Matter –Kinetic Molecular Theory –Four States of Matter –Thermal Expansion MATTER."— Presentation transcript:
Ch Solids, Liquids, & Gases I. States of Matter –Kinetic Molecular Theory –Four States of Matter –Thermal Expansion MATTER
A. Kinetic Molecular Theory KMT –Tiny, constantly moving particles make up all matter. –The kinetic energy (motion) of these particles increases as temperature increases. –Temperature = AVERAGE kinetic energy of the particles in a system. –Heat = TOTAL kinetic energy of the particles.
B. Four States of Matter Solids –low KE - particles vibrate but can’t move around –definite shape & volume –crystalline - repeating geometric pattern (MOST solids) –amorphous - no pattern (e.g. glass, wax, obsidian) – it was frozen too fast to organize into crystals
B. Four States of Matter Liquids –higher KE - particles can move around but are still close together –indefinite shape –definite volume –Viscosity – resistance to flow. Motor oil, syrup have high viscosity; water, gasoline lower viscosity Heating the liquid reduces viscocity (warming syrup makes it flow easier)
B. Four States of Matter Gases –high KE (moving very fast) - particles can separate and move throughout container (99% empty space) –indefinite shape & volume
B. Four States of Matter Plasma –very high KE - particles collide with enough energy to break into charged particles (+/-) –gas-like, indefinite shape & volume –Stars (Sun), fluorescent light bulbs, TV tubes, lightning Most common state in the universe
C. Thermal Expansion Most matter expands when heated & contracts when cooled. Temp causes KE. Particles collide with more force & spread out. EX: thermostats (bimetallic strip) – two different metals, one contracts/expands more than the other.
Solid expansion, cont. Expansion joints in bridges, concrete,etc.
Expansion of liquids Alcohol or mercury in a (old style) thermometer expands with an increase in temperature.
Gas expansion Gases expand/contract the most of the states of matter. EX. Hot-air balloons. Air expands, becomes less dense, rises.
Ch Solids, Liquids, & Gases II. Changes in State –Phase Changes –Heating Curves MATTER
A. Phase Changes Melting –solid to liquid Freezing –liquid to solid melting point = freezing point ** The temperature of a substance CAN NOT change during a phase change.
Vaporization (two types) 1. boiling - liquid to gas at the boiling point & throughout the liquid 2. evaporation - liquid to gas below the boiling point, but only at the surface
Sublimation –solid to gas without becoming a liquid in between –EX: dry ice, freeze drying, iodine Condensation gas to liquid
A. Phase Changes
B. Heating Curves Kinetic Energy –motion of particles –related to temperature Potential Energy –space between particles –related to phase changes
B. Heating Curves Solid - KE Melting - PE Liquid - KE Boiling - PE Gas - KE
B. Heating Curves Heat of Fusion –energy required to change from solid to liquid –some attractive forces are broken
B. Heating Curves Heat of Vaporization –energy required to change from liquid to gas –all attractive forces are broken –EX: steam burns, sweating, and… the drinking bird HEATING CURVE
Ch Solids, Liquids, & Gases III. Behavior of Gases –Pressure –Boyle’s Law –Charles’ Law MATTER
A. Pressure Which shoes create the most pressure?
A. Pressure Key Units at Sea Level kPa (kilopascal) 1 atm 760 mm Hg 14.7 psi
A. Pressure Barometer Atmospheric Pressure Manometer Contained Pressure
A. Pressure Effect on Boiling Point –When atmospheric pressure decreases, the boiling point of a liquid decreases. –EX: high altitude cooking –Denver is 1 mile above sea level & water boils at 95 o C; –on Mt. Everest (5.5 miles high) 71 o C
Converting temperature units K = 0 C C = K – 273 What is the kelvin temperature of 20 o C? 20 o C ___________ = What is 20 K in celcius? 20 K _________ =
Boyle’s Law (temp constant) Pressure and volume are inversely proportional. i.e. if one goes up the other goes down. A decrease in the volume of gas will result in an increase in pressure An increase in the volume of gas will result in a decrease in pressure V 1 P 1 = V 2 P 2
P V PV = k B INVERSE
B. Boyle’s Law
V 1 =20 & P 1 = 30 P 2 = 120 V 2 = ? V 1 P 1 = V 2 P 2 (20)(30) = (V 2 )(120) 600 = (V 2 )(120) 600 = V = V 2
V 1 =50 & P 1 = 30 V 2 = 120 V 1 P 1 = V 2 P 2 (50)(30) = (120)(P 2 ) 1500 = (120) (P 2 ) 12.5 = P 2
Charles’s Law (pressure constant) Volume of a gas increases with increasing temperature Volume of a gas decreases with decreasing temperature V 1 = V 2 T 1 T 2
V T C. Charles’ Law When the temperature of a gas increases, its volume also increases (at constant pressure). DIRECT
C. Charles’ Law
Absolute Zero - Temp at which... –the volume of a gas would equal zero. –all particle motion would stop. -273°C or 0 K
Example #1 V 1 =20, T 1 = 30, & T 2 = 120
V 1 = V 2 T 1 T 2 20 = V /3 * 120 = V 2 80 = V 2
Example #2 V 1 =120, T 1 = 30, & V 2 = 300
V 1 = V 2 T 1 T = T * T 2 = 300 * * T 2 = 9000 T 2 = 75
Relating to Life Principle – Use Boyles (temperature constant) –Squeezing a balloon Charles (pressure constant) –Why balloons decrease in size when kept in a cold room –Reason for statement on hair spray: “keep away from heat, contents under pressure”
Problems #V1V2T1T ?69 6? ? ? Charles Law Boyles Law #V1V2P1P213015? ? 3? ?34102
Answers #V1V2T1T Charles Law Boyles Law #V1V2P1P