1. Regents Chemistry 2014

2.   Anything that has mass and takes up space  3 states/phases of matter  Solid  Liquid  Gas Lesson 1:What is matter?

3.   Particles tightly packed together  Particles move by vibrating in place  Have definite shape and definite volume Solids Page 1

4.   Particles are moderately packed together  Particles vibrate and rotate  Have no definite shape, take the shape of their container  Have definite volume Liquids Page 1

5.   Particles are loosely packed  Particles vibrate, rotate, and bounce off of their container and each other  Have no definite shape  Have no definite volume Gases (Vapors) Page 1

6.  Change from SOLID to LIQUID Heat is absorbed (ENDOTHERMIC rxn) Molecules spread out “ Fusion ” No temp change even though energy is added Average KE of particles remains the same Particles absorb heat as Potential Energy Melting (fusion) Page 2

7.  Change from LIQUID to SOLID Heat is removed (EXOTHERMIC rxn) Molecules get closer “Solidification” No temperature change Potential Energy decreases Freezing (solidification) Page 2

8.  Change from LIQUID to GAS Heat is absorbed Molecules spread out “Vaporization” No change in temp but particles gain potential energy Evaporation (vaporization) Page 3

9.  Change from GAS to LIQUID Heat is removed Molecules get closer Condensation Page 3

10.  Sublimation : Change from SOLID to GAS, skips liquid step Molecules spread out Deposition : GAS to SOLID, skips liquid step Molecules get closer Sublimation/Deposition Page 3

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12.   Energy: the ability to do work or produce heat Types: electromagnetic (radio waves, microwaves, etc.), heat, mechanical, chemical, nuclear  Potential energy (PE) : stored energy held in chemical bonds (attachments) between atoms  Kinetic energy (KE) : the energy of motion Lesson 2:Energy Changes with Phase Changes Page 10

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14.   Temperature : Measure of average kinetic energy of the particles of a substance  Need two reference points to establish temperature scale  Heat is the flow of energy due to a temperature difference  Heat always flows from high temp to low temp Energy Changes Associated with Phase Changes Page 10

15.   Kelvin Temperature : scale that is directly proportional to average KE (See Table T ) K = °C + 273  0 °C = ? K ______________________  100°C = ? K ______________________  50 K = ? °C _______________________ Kelvin temperature scale

16.  Graphs of Temperature vs. Time Show the phase changes of a substance Time increasing as temp stays constant (no slope) represents a phase change Places with slopes indicate temperature changes Heating/Cooling Curves

17.  Heating Curve Energy

18.  1.What caused the water to change phases during this experiment? Heating the water 2. What is happening at the two plateaus on the graph? Phase changes 3. Why doesn’t the temperature change at these spots? Average kinetic energy is constant 4. The melting point of water occurs at the same temperature as the _________ point of water. Freezing 5. What other pair of phase changes happens at the same temperature? Evaporation and condensation

19.  Label: -solid, liquid, gas -evaporation -melting -between which points is kinetic energy increasing? -where is potential energy increasing? Do Now: Heating Curve

20.  Cooling Curve

21.  1.Freezing point: 2.Boiling point: 3.Melting point: 4.Range where solid is warming: 5.Range where liquid is warming: 6.Range where vapor is warming: 1. Melting of the solid: 2.Vaporization of the liquid: 3.Change(s) in potential energy: 4.Change(s) in kinetic energy: Page 6 1.Condensation: 2.Crystallization:

22.   Work on packet pages 7 and 8, then we’ll go over  https://www.youtube.com/watch?v=DhZ3r9qp7 Ik Homework

23.   Do Now: Take out homework On this curve: 1) Where is kinetic energy increasing? 2) Where is potential energy increasing? Lesson 3: Heat Formulas

24.   For temperature changes ( heating or cooling) use formula q=mc Δ T  q = heat, in “joules”  m = mass, in “grams, g”  c = “Specific heat of water,” 4.18, on Table B  Δ T = change in temperature (Celsius or Kelvin),  T final – T initial Formula for all Temperature Changes Formula is on Table T Last thing on page 10

25.  1. How many joules of heat are needed to raise the temperature of 25g of water from 30°C to 70°C ? q=mc Δ T q = m = c = Δ T = T final - T start q = heat, in “joules” m = mass, in “grams, g” c = “Specific heat of water,” 4.18 ΔT = change in temperature, T final – T initial

26.  2. If 420 J of heat are added to 20g of water, how many degrees will the temperature increase? q=mc Δ T q = m = c = Δ T = T final - T start q = heat, in “joules” m = mass, in “grams, g” c = “Specific heat of water,” 4.18 ΔT = change in temperature, T final – T initial

27.  3. The temperature of a sample of water rises from 298 K to 308 K by the addition of 84 J of heat. What is the mass of the water sample? q=mc Δ T q = m = c = Δ T = T final - T start q = heat, in “joules” m = mass, in “grams, g” c = “Specific heat of water,” 4.18 ΔT = change in temperature, T final – T initial

28.  4. What will be the temperature change (in Kelvin) of 150g of water if 3150 joules of heat are absorbed? q=mc Δ T q = m = c = Δ T = T final - T start q = heat, in “joules” m = mass, in “grams, g” c = “Specific heat of water,” 4.18 ΔT = change in temperature, T final – T initial

29.  5. How many joules of heat are removed from 50g of water when it cools from 90°C to 50°C ? q=mc Δ T q = m = c = Δ T = T final - T start q = heat, in “joules” m = mass, in “grams, g” c = “Specific heat of water,” 4.18 ΔT = change in temperature, T final – T initial

30.  6. If 42000 J of heat are added to 10g of water at 273 K, what will be the final temperature of the water? q=mc Δ T q = m = c = Δ T = T final - T start q = heat, in “joules” m = mass, in “grams, g” c = “Specific heat of water,” 4.18 ΔT = change in temperature, T final – T initial

31.  Lesson 4: The Other Heat Calculations

32.   For temperature changes  What about times where temperature doesn’t change? q=mc Δ T

33.  Heat of Fusion : amount of heat needed to MELT a solid under normal conditions. Freezing needs the same amount of energy. Fancy Heat Terms (and symbols!) Back to page 2 HfHf Value for H f is on Table B in Reference Tables

34.   Heat of Fusion, q=mH f : use for solid-liquid changes Key words: melting, freezing, solidification, crystallization Value for water is on Reference Table B q = heat, in “joules” m = mass H f = Heat of Fusion Heat of Fusion Formula

35.  1) How many joules of heat are needed to melt 50g of ice at 0°C? q=mH f q = m = H f = H f examples q=mH f q = heat m = mass H f = Heat of Fusion, 334 J/g

36.  2) How many grams of ice can be melted by the addition of 92852 joules of heat? q=mH f q = m = H f = H f examples q=mH f q = heat m = mass H f = Heat of Fusion, 334 J/g

37.  3) When 20g of a substance is completely melted at 0°C, 3444 J are absorbed. What is the heat of fusion of this substance (which isn’t water)? q=mH f q = m = H f = H f examples q=mH f q = heat m = mass

38.  Heat of Vaporization : amount of heat needed to turn LIQUID to GAS under normal conditions. Condensation needs the same amount of energy. Fancy Heat Terms (and symbols!), Part 2 Back to page 3 HvHv Value for H v is on Table B in Reference Tables

39.   Heat of Vaporization, q=mH v : use for liquid-gas changes Key words: evaporation, vaporization, steam, condensation This value for water is on Reference Table B q = heat, in “joules” m = mass H v = Heat of Vaporization Heat of Vaporization Formula

40.  1) How many joules are needed to boil 25g of water at 373 K? q=mH v q = m = H v = H v examples q=mH v q = heat m = mass H v = Heat of Vaporization, 2260 J/g

41.  2) What mass of water vapor will condense if 99440 J are removed at 100°C? q=mH v q = m = H v = H v examples q=mH v q = heat m = mass H v = Heat of Vaporization, 2260 J/g

42.  3) It takes 2.259 x 10 3 J of heat to vaporize 684g of a substance. What is the heat of vaporization of this substance (which is not water)? q=mH v q = m = H v = H v examples q=mH v q = heat m = mass

43.   q=mc Δ T for temperature changes in one phase  q=mH f for melting or freezing  q=mH v for boiling/evaporation or condensation Which Formula Do You Use?

44.  q=mc Δ T q=mH f q=mH v 1) How many grams of ice would melt with 1.668 x 10 3 joules of heat?

45.  q=mc Δ T q=mH f q=mH v 2) If 840 J of heat are added to 20g of water and the temperature increases to 70°C, what was the initial temperature of the water?

46.  q=mc Δ T q=mH f q=mH v 3) How many joules of heat are needed to evaporate 500g of water?

47.   Posted book questions, # 30-32 & 34-40 Homework