Honors Chemistry - Unit 10 Chapters 10 & 12 Kinetic Molecular Theory (KMT) VOCABULARY:

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1 Honors Chemistry - Unit 10 Chapters 10 & 12 Kinetic Molecular Theory (KMT) UT Quest Due Date(s): VOCABULARY: Test Date: Unit 10 Packet - Page 1 of 14 Absolute Zero- no molecular movement at this temperature (0 K, C) Amorphous- non-crystalline substance such as glass that appears to be solid but is a super cooled liquid Anhydrous - without water Barometer- a manometer used to measure atmospheric pressure Condensation- change in state from a gas to a liquid Deposition change in state directly from a gas to a solid Diffusion mixing of 2 or more gases Effusion movement of a gas through a small opening Evaporation- change in state from a liquid to gas Fluids gases and liquids, flow Ideal gas imaginary gas that fits all the assumptions of the kinetic molecular theory Kelvin SI unit of temperature Kinetic Theory- group of ideas explaining the interaction of matter and energy due to particle motion Melting change in state from a solid to a liquid Molar heat of fusion heat needed to melt one mole a substance at its melting pt Molar heat of vaporization Heat needed to vaporize one mole of a substance at its boiling pt. Plasma- high energy state of matter composed of ions that are knocked apart by collisions Pressure - the number and speed of collisions on a wall of a container States of Matter- solid, liquid, gas, and plasma are the four states of matter STP standard temperature and pressure Sublimation -change in state directly from a solid to a gas Surface tension- the apparent skin on surface due to forces holding a liquid together Triple point all three major states of matter are in equilibrium at this temperature and pressure Vapor- gaseous state for substances that are normally a liquid or a solid at room temperature Viscosity- resistance of liquids to flow Volatile a liquid that evaporates readily OBJECTIVES: Be able to list and explain the basic assumptions of kinetic theory. Be able to define pressure and memorize the basic pressure units. Be able to convert to/from: atms, kpa, Pa, mm Hg, torr. Differentiate between the four states of matter. Be able to identify and name the changes of state. Be able to read a phase diagram and identify the triple point. Be able to describe surface tension and capillary action Understand the concept of atmospheric pressure and its affect on boiling point. Understand the properties of water due to hydrogen bonding. Be able to label a boiling point/freezing point graph Be able to do a heat of fusion and heat of vaporization problem. Be able to describe in detail properties of solids, liquids and gases Be able to relate the above properties to the KMT

2 Unit 10 Packet - Page 2 of 14 KMT & Phase Changes of Matter (Prentice Hall Chemistry Chapters 13, 14.1, 14.3, &15.1) (Modern Chemistry Chapters 10 & 12) Objectives: 1. Encourage self acquisition of information and knowledge. 2. Encourage independent and cooperative learning 3. Improve organizational, note taking, and study skills 4. Understand and apply the Kinetic Molecular Theory to the properties of solids, liquids, and gasses. Overview: 1. Learning stations-ten (10) learning stations will be visited by the pre-assigned learning groups. Each station will cover a topic and will require a specific output. 2. Phase Change of Matter Laboratory. Learning Groups will perform a simple laboratory experiment and individually graph the results and write the conclusions. 3. Phase change of water discussion and energy changes. Teacher led discussion of the experiment and of the energy changes involved. 4. Phase Diagram interpretation and work. Learning group directed investigation of the phase diagram of water and application of that knowledge to other phase diagrams. 5. Review Test-self directed review of the material and 6. Practice essays (review Station Eight) Output: 1. Daily participation grades these may be announced or unannounced. 2. Organized portfolio of the unit work: ( you will get a combined lab grade for mini-lab activities). This portfolio is primarily your COMPLETED unit packet. Any work that is not completed in the packet (on your own paper) must be attached in an organized, labeled manner. 3. Phase Change of Matter Lab write up. (lab grade) 4. Practice essays must be completed (review Station Eight) 5. All due on the day of the Unit test!

3 Unit 10 Packet - Page 3 of 14 Detailed Station Instructions & Overview for Kinetic Molecular Theory You will work with pre-assigned co-operative learning groups. You will work for 4-5 days with your groups (with about minutes at each station and free station time at the end). If you are absent, you will need to come to class and make-up the work on your own time. At the end of the unit, we will finish with group work and talk about a few topics as a class. If you finish a station early work with your partners on your problem set. Station One: Kinetic Molecular Theory. You will read about the kinetic molecular theory and work on a worksheet. Reference: Prentice Hall Chemistry pages page and Modern Chemistry pages Station Two: Vocabulary: Each student should independently review the definitions of the given vocabulary words and complete the handout. Once the team is finished, they should take the definitions with them and play the CONCENTRATION GAME. Each group should play a couple of rounds of concentration with the cards face down. Each student picks a card and attempts to find the match (word or definition). If correct they keep the match and go again. Keep a tally of who wins, for your portfolio. Station Three: Liquids & Solids Complete the liquids & solids worksheet. Station Four: Mini-lab Read and complete the worksheet; then complete the mini-lab. Station Five: Energy changes: Read and take notes on section; then as a group do the boiling/freezing graph Station Six: Phase diagrams: Read pages while answering the questions on your worksheet. Then complete the phase diagram worksheet. Station Seven: Practice Essays: Read the handout and as a group, decide what part of the KMT you would use to answer the prompt for each essay. Station Eight: KMT Labs: Read and complete the worksheet; then complete the lab and answer the questions. Station Nine: Vapor Pressure and Boiling: Read and complete the worksheet; then complete the vapor pressure and boiling worksheet and answer the questions. Homework for all groups: Any unfinished assignments and UT Quest! As a class we will review this work and prepare for the test.

4 Unit 10 Packet - Page 4 of 14 I. Station One: KMT Worksheet The Kinetic Molecular Theory of Matter - Read Prentice Hall Chemistry pages page and Modern Chemistry pages individually. Then as a group work on the questions below: 1. What is an ideal gas? 2. What is the kinetic-molecular theory? 3. What are the five assumptions of the KMT? Define an elastic collision 5. If the temperature of a gas is increased what happens to the particles kinetic energy? 6. Explain the properties of expansion, fluidity, low density and compressibility. 7. Explain the difference between diffusion and effusion. 8. If a bottle of ammonia gas (NH3) and a bottle of Chlorine gas (Cl2) were opened at the same time, which would reach the back of the room first? Why? On pg 306 do # 2.

5 Unit 10 Packet - Page 5 of 14 II. Station Two: Vocabulary Concentration Game with vocabulary words. You may play the game AFTER you complete the following worksheet. Don t forget to keep a tally of who wins! KMT Vocabulary Worksheet Start in Ch. 13: P-H Chemistry text 13.1 Solid, liquid, gas, and plasma are the four of. Theory- group of ideas explaining the interaction of matter and energy due to particle motion Pressure- - an empty space with no particles and no pressure Barometer- a. SI unit of temperature Pascal (Pa)- - the temperature at which there is no molecular movement standard temperature and pressure (273 K and 1 atm) liquid to gas below its boiling point Vaporization- -gas to a liquid Vapor Pressure- - the temperature at which the vapor pressure of a liquid is just equal to the external pressure. Normal Boiling Point solid to a liquid -liquid to solid (solidification) - non-crystalline substance such as glass that appears to be solid but is a super cooled liquid -two or more different molecular forms of the same element changing directly from solid to a gas Point all three major states of matter are in equilibrium at this temperature and pressure gas imaginary gas that fits all the assumptions of the kinetic molecular theory 15.1 Surface tension-

6 III. Station Three: Liquids and solids Unit 10 Packet - Page 6 of 14 Read pgs , (373, 378, 379, 380) (Modern Chemistry) these contain vocabulary for this section; you do not have to read these pages just use them for the vocabulary and answer the following questions: (bold pages are in P-H textbook) 1. Liquids have a definite and take the shape of (indefinite shape) p 363 (p 390) 2. How do the attractive forces between liquids compare to the attractive forces in solids? p 367 (p 396) 3. What is a fluid? What type of matter falls under the fluid category? p Give at least 4 properties of liquids describe each. p Define vaporization and evaporation. 6. Describe the attractive forces found in solids. p What is the difference between a crystalline solid and an amorphous solid give examples of each. p Give at least 4 properties of solids describe each. p Define: condensation, boiling, freezing, sublimation and deposition. IV. Station Four: Mini-lab - Water and Its Properties Read Ch. 15.1, pages in P-H Chemistry and Read pgs 365 in Modern Chemistry. Answer the following questions in your notes and then complete the mini-lab for the lab you do not have to do a formal write-up. Just record observations and answer these questions. 1. Define surface tension and capillary action. 2. Why does ice float on liquid water? Mini-lab: Procedure: 1. Add tap water to a beaker until it is nearly full. 2. Carefully place a paper clip on the surface of the water. Hold the paper clip around the edge and gently and evenly place it on the surface. If you can not get it to float, ask your teacher for help. QUESTION 1. What happens? Why? 3. Add one drop of soap to the water (place the drop away from the clip, NOT on top of it soap is at the side by the sinks). QUESTION 2. What happens? Why? 4. Pick up a straw from the center table. 5. Place the straw in a half full beaker of colored water. QUESTION 3. What happens to the level of the water in the straw? Why?

7 V. Station Five: Energy and Changes of State Unit 10 Packet - Page 7 of 14 Read pgs in Modern Chemistry; omit the section on Le Chatelier s Principle and equilibrium, temp, and conc. pg we will cover this in more detail later this year! Define: volatile molar heat of vaporization molar heat of fusion As a group, complete the worksheet that is called Freezing And Boiling Point Graph we will go over this together as a class. Freezing And Boiling Point Graph Answer the following questions using the chart above. 1. What is the freezing point ( C) of the substance? 2. What is the boiling point ( C) of the substance? 3. What is the melting point ( C) of the substance? 4. What letter represents the range where the solid is being warmed? 5. What letter represents the range where the liquid is being warmed? 6. What letter represents the range where the vapor is being warmed? 7. What letter represents the melting of the solid? 8. What letter represents the vaporization of the liquid? 9. What letter(s) shows a change in potential energy? 10. What letter(s) shows a change in kinetic energy? 11. What letter represents condensation? 12. What letter represents solidification?

8 Unit 10 Packet - Page 8 of 14 VI. Station Six: Phase Diagrams Read the Phase Diagram Explanation Below. Define: phase diagram triple point critical point critical temperature critical pressure Phase Diagram Explanation (water) Much of the information we have discussed can be shown in a phase diagram, which shows how the states of matter in a system are affected by changes in temperature and pressure. Figure 7.9 is a phase diagram for water. Each colored area represents all of the conditions under which water in that phase can exist. The solid-vapor line, AB, gives the temperatures and pressures at which solid water and water vapor are in equilibrium. This line represents the equilibrium vapor pressure of ice at temperatures from -79 C to point B. The liquid-vapor line, BD, gives the temperatures and the pressures at which liquid water and water vapor are in equilibrium. This line represents the equilibrium vapor pressure at liquid water at temperatures from point B to 374 C. Point B is called the triple point because all three states are in equilibrium at this temperature and pressure (0.01 C and kpa). Point D represents the critical point; above this point, there is no vapor pressure curve. Only the gaseous state exists at pressures and temperatures above this point. T m is the normal melting point, which occurs where BC, the solid-liquid equilibrium line, is cut by the standard atmospheric pressure line. T b, the normal boiling point, is that temperature at which the liquid-vapor equilibrium curve is cut by the pressure line of kpa. Only the solid-vapor, AB, and the liquid-vapor, BD, lines represent vapor pressure information. The line BC simply indicates the pressure-temperature conditions under which the solid and liquid can be in equilibrium. The solid-liquid equilibrium line, BC, for water has a negative slope, indicating that a rise in pressure lowers the freezing point. Recall that water expands when it freezes. Most substances contract when they freeze and their solid-liquid equilibrium lines have positive slopes, such as that for hydrogen in Figure Merrill Chemistry p

9 As a group complete the phase diagram worksheet. Unit 10 Packet - Page 9 of 14 Phase Diagram Worksheet Answer the following questions using the chart above. 1. What section represents the solid phase? 2. What section represents the liquid phase? 3. What section represents the gas phase? 4. What letter represents the triple point? 5. What letter represents the critical point? 6. What is this substance's normal melting point? 7. What is this substance's normal boiling point? 8. Above what temperature is it impossible to liquefy this substance no matter what the pressure? 9. At what temperature and pressure do all three phases coexist? 10. Is the density of the solid greater than or less than the density of the liquid? 11. Would an increase in pressure cause this substance to freeze or melt?

10 VII. Station Seven: Essays Unit 10 Packet - Page 10 of 14 Given a problem from below, analyze it using the kinetic molecular theory. Some of the exact same essays will appear on the test we will go over some of these as a group. Must write 3-4 complete sentences for each essay to get credit. A: Your teacher walks into the always hot chemistry room, you are sitting in the back of the room, after a few minutes you can smell the perfume your teacher is wearing, explain why. B: If you have a balloon filled with helium and a second balloon filled with the same amount of nitrogen; a small identical leak occurs in both balloons which will deflate first and why? C: Why does ice float on water? D: Why are there special directions on some baked goods for high altitudes? Would it be easier to make macaroni and cheese in Denver or in Wilmington? Explain. E: What conditions cause a gas to deviate from ideal behavior? Why does this happen? F: Which would you expect to occupy the most space, 1g of liquid water or 1g of water vapor? Why?

11 Unit 10 Packet - Page 11 of 14 G: Imagine you have been shrunk down so that you can ride on an ideal gas particle. Please describe the five basic assumptions of the KMT from your new perspective. H: Ethanol and water have different normal boiling points and vapor pressures at the same temperatures. How can you explain that Ethanol has a higher vapor pressure while water has a lower vapor pressure at the same temperature? Which substance would have a higher normal boiling point? I: Please explain why if you cook rice in a pressure cooker you can have finished rice in about 1/3 the time of cooking it at atmospheric pressure? J: Your chemistry teacher has just made the statement that when you ice skate you are really skating on liquid water. Assume he is correct. Using the phase diagram of water, please explain this phenomenon. K: Which would you rather have a burn from, water at 100 C or a burn from steam at 100 C? Why?

12 Unit 10 Packet - Page 12 of 14 VIII. Station Eight: Labs for Kinetic Molecular Theory Unit: Chromatography, Cold Water Boils and Surface Tension Answer the pre-lab questions, complete the lab and answer the post-lab questions. Pre-lab questions: 1. Define chromatography. 2. What kind of information can you read from a phase diagram? 3. What is surface tension. Give an example. Procedures: Chromatography Equipment: goggles 1 large test tube test tube rack filter paper strips Washable black pen (use your teacher s pens!) Procedure: 1. Use a pencil to mark a small circle, the size of the printed letter o, about 2 cm from one end of a piece of filter paper strip. (strip should be long enough to go from the bottom to the top of your test tube and the sides of the strip should not be bent when placed in the test tube). 2. Place a dot of black ink into the o. allow the ink to dry. 3. Fill a test tube with water to a little less than 2 cm. 4. Place the filter paper strip into the test tube. The end of strip should be below the water level; the dye spot must be above the water level (do not allow it to get wet!) 5. Set the tube to the side where it will be allowed to sit for the rest of the period. 6. Do the other two labs while the water moves up the paper! Come back to this procedure at the end 7. At the end of the lab, go back to your tube and pull out your filter paper. Cold Water Boils! Anyone who uses their syringe to spray water at anyone else will lose their lab privileges and will receive a zero for their lab grade! 1. Obtain a plastic syringe from the center table. Remove the cap. 2. Draw in 5 to 6 cc of tap water. 3. Holding the syringe with the tip up, gently press on the plunger until no air remains in the syringe. You may need to tap on the syringe to get all the air bubbles out. 4. Seal the tip of the syringe by covering the opening tightly with your thumb. 5. Pull on the plunger to enlarge the volume of space occupied by the water. 6. Record any observations (hint you should see some bubbles!) 7. Slowly allow the plunger to return to its original position. 8. Repeat if necessary. A look at Surface Tension 1. Fill a beaker almost full of tap water. 2. Add a dash or two of pepper to the water. Add enough so you can see it. 3. Record observations. 4. Add a drop of soap to the surface of the water. 5. Record observations 6. Clean up. 7. Remember to go back and finish the chromatography lab.

13 Unit 10 Packet - Page 13 of 14 Questions (for all three experiments in Station VIII): 1. What happened to your filter paper in experiment 1. Explain. 2. Classify the black ink as an element, compound, solution or heterogeneous mixture. 3. How did you draw the above conclusion? 4. Think of another application of chromatography. 5. What did you observe with the water in experiment What change of state was occurring? 7. How was this possible at room temperature? 8. What happened when you added the soap to pepper water? Why? Error Analysis List at least 3 possible errors in this lab (at least one for each experiment). Be sure to explain the effect the error would have on your lab results. IX. Station Nine: Vapor Pressure & Boiling Pressure and Cooking Most any packaged food that involves boiling (like boxed macaroni-and-cheese dinners) will have "high altitude" cooking instructions. I have here a box of Hamburger Helper that says: High Altitude ( ft): Decrease hot water to 3-3/4 cups. Increase simmer time to 17 minutes. The reason foods have these instructions is because the boiling point of water changes with altitude. As you go higher, the boiling temperature decreases. At sea level, the boiling point of water is 212 degrees F (100 degrees C). As a general rule, the temperature decreases by 1 degree F for every 540 feet of altitude (0.56 degrees C for every 165 meters). On top of Pike's Peak, at 14,000 feet, the boiling point of water is 187 degrees F (86 degrees C). So pasta or potatoes cooked at sea level are seeing 25 degrees more heat than pasta or potatoes cooked on Pike's Peak. The lower heat means a longer cooking time is needed. Pressure cookers work in the opposite direction. A pressure cooker raises the pressure so that the water boils at a higher temperature. A typical pressure cooker applies 15 pounds of pressure, so the boiling point of water rises to 250 degrees F (121 degrees C) at sea level. The higher temperature means that foods take less time to cook. You may already know about the relationship between temperature and pressure: When you pressurize air (or any gas), it gets hotter, and when you release the pressure on air it gets colder. So a bicycle pump gets hot when you pump up a tire, and a spray paint can or a C0 2 cartridge gets cold as you release the pressurized gas. A refrigerator puts both of these processes together, pressurizing gas on the outside of the refrigerator to release heat and decompressing it inside the refrigerator to absorb heat (see How Refrigerators Work for details). You may also know that air pressure decreases as altitude increases. This table shows the pressure (in pounds per square inch) at different altitudes: Altitude Sea level Air Pressure 14.7 PSI 10,000 feet 10.2 PSI 20,000 feet 6.4 PSI 30,000 feet 4.3 PSI 40,000 feet 2.7 PSI 50,000 feet 1.6 PSI As air rises, the pressure decreases. It is this lower pressure at higher altitudes that causes the temperature to be colder on top of a mountain than at sea level. From howstuffworks.com

14 Unit 10 Packet - Page 14 of 14 Vapor Pressure & Boiling A liquid will boil when its vapor pressure equals atmospheric pressure. Answer questions following the graph. 1. At what temperature would Liquid A boil at an atmospheric pressure of 400 torr? 2. Liquid B? 3. Liquid C? 4. How low must the atmospheric pressure be for Liquid A to boil at 35 0 C? 5. Liquid B? 6. Liquid C? 7. What is the normal boiling point of Liquid A? 8. Liquid B? 9. Liquid C? 10. Which liquid has the strongest intermolecular forces?