# Activity 5 At a Glance

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 At a Glance Testing Your Hypothesis by Boiling Water Below Its Boiling Temperature Purpose To have students boil water below its typical boiling temperature by reducing the pressure above the surface of the liquid Overview Groups discuss ways to reduce the boiling temperature of water and present their best idea. After discussing each idea, groups select an approach, write a procedure, and follow it. Students find that water can boil well below its typical boiling temperature. They try to make sense of their observations and discuss their conclusions in their groups. Next, the teacher gives the students a phase diagram for water without telling them what it is. The groups study it and write a caption for it based on what they think it shows. Through a discussion, the students learn about phase diagrams and use them to better understand their previous work with pressure and changes of state. Finally, the students hypothesize about the effects of different elevations and weather conditions on the boiling point of water. Key Concept Water boils when its vapor pressure equals atmospheric pressure. As a result, water s boiling temperature is pressure, rather than temperature, dependent. Context for This Activity Mars has such low atmospheric pressure that any water at the surface would boil away. In this activity, students see that they can get water to boil below its typical boiling temperature when they drop the pressure in a closed container. By extrapolating the pattern between boiling temperature and pressure, they realize that even water near its freezing point has enough kinetic energy to boil if the pressure is low enough. Skills Predicting the outcome of an experiment Developing a hypothesis Writing a procedure to test a hypothesis Controlling variables Conducting an experiment Using a phase change diagram Collecting, recording, and graphing data Drawing conclusions and communicating them to others Common Misconceptions Boiling is a process that is controlled solely by the heat source. Pressure has no bearing on water s boiling temperature. Materials Heat source, 500- or 1,000-milliliter round-bottomed, thick-walled (for example, Florence) flask, three-hole stopper, plastic tubing, thermometer, 100 cc or larger air piston (syringe), ring stand or tripod, ring clamps, thermometer clamp, stirring rod, wire gauze (burners only), graph paper, goggles, appropriate safety equipment. Preparation Plan how to present the initial problem and the best way to develop a procedure. Insert thermometers in the rubber stoppers. Set out the necessary equipment for each group. Make sure the glassware is heavy-duty enough to withstand considerable pressure. Discuss safety procedures related to heat sources, thermometers, glassware, pressurized containers, and hot water. Time: 2 3 class periods EG HQ 35

2 Background In Activity 3, students raised the boiling temperature of water by increasing the pressure above the water. To vaporize in the pressurized container, the water molecules needed to increase their kinetic energy. This increase in kinetic energy translated into a higher boiling temperature. Activity 5 is a natural extension of this earlier work. In this activity, students find ways to reduce the temperature of the water-to-vapor plateau. By challenging students to reduce water s boiling temperature, they must apply their understanding to a related, but new, situation. Their hypotheses will reveal how well they understand the relationship between pressure and boiling temperature. Just how do you reduce water s boiling temperature? You can do this by reducing the pressure above the water. With a reduced pressure, the water molecules need less kinetic energy to vaporize than they do in an open container. This decrease in kinetic energy translates into a lower boiling temperature. Whether water exists as a solid, liquid, or gas depends on its temperature and the pressure of the surrounding environment. Change the temperature or pressure, and water may undergo a phase change. We are familiar with how water responds to changes in temperature at sea level, it typically freezes at 0 degrees Celsius and boils at 100 degrees Celsius. However, we are less familiar with how water responds to changes in pressure (recall Figure 4.1). Researchers have measured the phase changes of water over a wide variety of temperatures and pressures. The resulting graph is called a phase diagram (Figure 5.1). ice at 0º C water at 0º C water water vapor Figure 5.2. Water is in equilibrium with ice when it freezes at the same rate that the ice melts (a). It is in equilibrium with vapor when it evaporates at the same rate that the vapor condenses (b). Every substance has its own unique phase diagram. At a boundary line between two phases, two phases are in equilibrium with one another that is, the rate of molecules leaving a particular phase equals the number returning (Figure 5.2). We refer to the inclination of a molecule to change phase and establish an equilibrium as its vapor pressure. Vapor pressure increases with increasing temperatures. At higher temperatures, a particle s kinetic energy is higher, and, with more energy available at higher temperatures, it is easier for particles to change phase. Even solids such as ice have a vapor pressure and can sublimate directly to the vapor phase. If two phases are not in equilibrium, molecules will change from one phase to the other until an equilibrium is established. The water evaporating out of a lake in the desert is trying to establish an equilibrium with the dry desert air. In the case of a puddle, the water disappears completely before an equilibrium is established. Each temperature-pressure combination has its own equilibrium point. If you connect these many equilibrium points, you will have drawn the boundary lines on the phase diagram Pressure (mb) 6.1 Solid Liquid Vapor Triple Point 100 Temperature ( o C) Boiling Point at Sea Level All three boundary lines meet at a point called the triple point. At this temperature and pressure, all three phases are in equilibrium with one another. In other words, at the triple point, vapor sublimates to ice and condenses to liquid, liquid evaporates to vapor and freezes to ice, and ice melts to liquid and sublimates to vapor all at the same rate. A minuscule change in either temperature or pressure will move the phase changes away from the triple point. Away from the boundary lines, water exists in a single phase over a particular range of temperatures and pressures. Figure 5.1. A phase diagram shows the equilibria among the three phases of water. At the triple point, the vapor pressure of ice, water, and water vapor are equal. Because a phase diagram shows so clearly how water changes phase in relation to pressure and temperature lev- 36 EG HQ

3 Activity 5 els, it is the key to helping students understand the current situation with liquid water on Mars. In fact, a phase diagram contains the essence of this entire module! On the phase diagram, notice that below 6.1 millibars, liquid water cannot exist, irrespective of the temperature. Water s vapor pressure is just too high to remain a liquid below this level. When atmospheric pressure falls below 6.1 millibars, water can only exist as ice or vapor, depending on the temperature. This fact is significant in our study of Mars because the atmospheric pressure at the Martian surface hovers just above 6.1 millibars. Any water that might form on a warm afternoon from melting ice would quickly disappear in the desiccated Martian atmosphere. If the vapor pressure of the warmed water exceeded atmospheric pressure, it would boil. If, instead, its vapor pressure stayed below atmospheric pressure, the water would evaporate. The temperature and pressure combinations on Mars make liquid water theoretically possible on an occasional basis. However, the desiccated atmosphere and the short-term nature of the appropriate temperature-pressure conditions make the existence of significant amounts of water on the Martian surface impossible (Figure 5.3). they make no distinction between liquid and gaseous water, even though we teach about states of matter. Consider addressing this common misconception during the activity. So, there are actually two reasons why low pressures are associated with rainy weather a humid air mass weighs less than a dry air mass, and a low pressure system rises to a lower altitude than a highpressure system (that is, it is not as tall). Use the phase diagram to answer questions about cooking modifications, the boiling of eggs, and water sterilization. Whenever the pressure changes, there is a corresponding change in water s boiling temperature. People living at high altitudes use pressure cookers, cook foods longer, or modify their recipes to compensate for the lower boiling temperatures. In fact, Galileo used differences in boiling temperature to calculate elevation. Students might try to predict the weather or measure elevations using water s boiling temperature. On Earth, propane, butane, dry ice, ether, and freon are familiar materials whose vapor pressure is considerably higher than Earth s atmospheric pressure. Toy stores often sell freon-filled perpetual drinking birds and globes containing freon that can boil when held in one s hand. Bring these or a butane lighter into class and discuss what is happening inside. On Mars, water would behave the way freon and butane behave on Earth. Something to be alert to when discussing weather-related pressure changes is the fact that humid air weighs less than dry air. This is because water vapor (H 2 O) weighs less than gaseous nitrogen (N 2 ). Because liquid water weighs more than air, students invariably say that humid air weighs more than dry air. This response reveals that Figure 5.3. This image of Mars shows that the Martian surface is currently dry. EG HQ 37

4 Activity 5 Preassessment (a) Students Take a Position and Become Aware of Their Preconceptions: Ask students: How low can air pressure on Earth be lowered? What happens when one lowers the air pressure over some liquid water? (b) Students Expose Their Beliefs: Have each student write down his or her prediction, sign his or her name, and hand it in to the teacher. Procedure to Test Students Preconceived Ideas 1. At the end of Activity 3, each group developed a hypothesis about the relationship between pressure and water s boiling temperature. For this lab, ask students groups to suggest procedures to reduce the boiling temperature of water. 2. Have each group present its best idea for how to reduce the boiling temperature of water and explain how its approach works. List the ideas on the board, and have the class identify the ones that achieve the objective and are testable in the classroom. If students suggest some feasible, nonpressure-related ideas, decide whether you want the groups that came up with them to test their procedures. Doing so maintains student ownership of the problem but risks extending the time required to complete the unit. Record any unused hypotheses for future projects. 3. Depending on time, equipment, and the nature of the suggested procedures, decide which approach below best fits your situation: Have each group select a feasible idea, write a procedure, and follow it. As a class, select a feasible idea, write a procedure together, and have each group follow it. Write a procedure as a class, and then perform it as a demonstration (see Figure 5.4). a. Pull Out Figure 5.4. These figures show two ways to cause boiling at temperatures below 100 degrees Celsius by reducing the pressure in a sealed container. Figure a shows how a syringe can be used to reduce the internal pressure and restart the boiling process. Figures b e show how to reduce pressure by condensing vapor (Figures d and e are alternate ways to cool the water heated in Figures b and c). b. c. d. cool water e. wrap a cold, wet towel around flask 38 EG HQ

5 Activity 5 Writing a procedure as a class enables you to discuss the elements of a complete procedure and to highlight safety concerns. If groups each write their own procedures, you may want to check the procedures for dangerous practices before having students begin. Writing the procedure can also be assigned as homework and discussed at the start of the next class, either in groups or as a class. The appeal of a demonstration is its efficiency. However, research shows that students retain ideas best when they play an active role. A demonstration robs students of the direct involvement so crucial to experiencing and understanding an activity. 4. After groups complete the procedure, have them summarize their observations. 5. Have each student explain in his or her own way how water can boil by lowering the temperature of the flask. This step is vital in helping students resolve any conflicts between their preconceptions and observations. By making sense of the observations, students are forced to confront their earlier thinking and to accommodate a new concept. 6. Have students share their explanations in their groups. 7. Have groups summarize their conclusions and share them in a class discussion. 8. Without introducing it, distribute the two phase diagrams of water to each group. Have each group write a caption for the diagram based on what they think it shows. 9. Have groups share their captions in a class discussion. 10. Ask groups to explain how this diagram can be used to explain what happened in this activity and in Activities 1, 2, and Have students hypothesize about the effects of different elevations and weather conditions on the boiling point of water. Ask how they might test their hypotheses. Have students test their hypotheses by boiling water under different weather conditions and/or by contacting schools at very different elevations and comparing boiling temperatures. Questions to Probe Students Observations 1. How did you lower the boiling temperature of water? 2. What was the temperature of the water when it boiled? 3. Why did your approach enable water to boil below its typical boiling temperature? EG HQ 39

6 Analysis Questions This series of questions probes students assumptions and understanding of boiling. Use them as the basis of a discussion, for group work, or for homework. 1. Use the phase diagram to explain why, under the same weather conditions, it is harder to make hard-boiled eggs in Denver, known as the mile-high city, than in Miami, a sea-level city. 2. On rainy days, water s boiling temperature is several degrees lower than it is on dry days. Also, water at sea level boils at a higher temperature than water at higher elevations. Why does boiling temperature vary? 3. How could you use boiling temperature to predict weather or determine elevation? 4. How might recipes need to be modified for mountain cooking? 5. Why is it hard to sterilize drinking water by boiling it at a higher elevation? 6. Will water always boil at the same temperature in your kitchen? Why or why not? 7. How could you get water to boil at its freezing temperature? Lower the pressure to the triple point. 8. What do you think water would look like at the triple point? Water can change phase only after crossing a boundary line. Therefore, it would remain in its current phase until it crossed a boundary line. However, the three phases are in equilibrium at the triple point. As a result, the water would change phase in order to establish an equilibrium between all three phases over time. 9. Why does water not boil at room temperature? What stops it from turning into a vapor? 10. Suppose you are on a climbing expedition to the top of Mount Everest. Near the top you decide to pause and boil tea for lunch. What can you predict about the process of boiling here? Would the tea burn your mouth? 11. Write a paragraph comparing how you answered the preassessment question with how you would answer it now. 12. At the start of this unit, you were asked to write down how hot could you heat water given unlimited time and heating equipment. How would you respond to this question now? 40 EG HQ

7 Pressure (mb)

8 Pressure (mb) Detail of the Phase Diagram of Water from 1 C to 2 C

### Educational Product. National Aeronautics and Space Administration. Educators. Grades 9 12 EG-2000-03-121-HQ. burning paper.

Push In National Aeronautics and Space Administration Educational Product Educators Grades 9 12 large syringe 2-hole stopper shelled, hard boiled ard boiled egg egg burning paper Is There Water on Mars?

### Investigation M3: Separating Mixtures into Component Parts

Investigation M3: Separating Mixtures into Component Parts Goals: Use various methods to separate mixtures, make inferences from temperature/time graphs, and identify substances. 81 Activity M3.3: What

### A Teaching Unit for Years 3 6 children

A Teaching Unit for Years 3 6 children 1 SEREAD and ARGO: Concept Overview for Years 3-6 Teaching Programme This is the overview for the first part of the SEREAD programme link with ARGO. The overview

### Practical Applications of Freezing by Boiling Process

Practical Applications of Freezing by Boiling Process Kenny Gotlieb, Sasha Mitchell and Daniel Walsh Physics Department, Harvard-Westlake School 37 Coldwater Canyon, N. Hollywood, CA 9164 Introduction

### Energy Matters Heat. Changes of State

Energy Matters Heat Changes of State Fusion If we supply heat to a lid, such as a piece of copper, the energy supplied is given to the molecules. These start to vibrate more rapidly and with larger vibrations

### Multiple Choice For questions 1-10, circle only one answer.

Test Bank - Chapter 1 The questions in the test bank cover the concepts from the lessons in Chapter 1. Select questions from any of the categories that match the content you covered with students. The

### WEATHER AND CLIMATE practice test

WEATHER AND CLIMATE practice test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. What role does runoff play in the water cycle? a. It is the process in

### BSCS Science Tracks: Connecting Science & Literacy

BSCS Science Tracks: Connecting Science & Literacy Second edition, 2006 by BSCS Investigating Weather Systems Unit Overview 5415 Mark Dabling Blvd. Colorado Springs, CO 80919 719.531.5550 www.bscs.org

### An Online School for Weather. www.srh.noaa.gov/jetstream/atmos/ll_whatacycle_aquifers.pdf

JetStream An Online School for Weather Aquifers Aquifers Aquifers 1 3 5 Aquifers Aquifers Aquifers 2 4 6 /atmos/ll_whatacycle_aquifers.pdf There are over 35 lesson plans in the National Weather Service

### There is no such thing as heat energy

There is no such thing as heat energy We have used heat only for the energy transferred between the objects at different temperatures, and thermal energy to describe the energy content of the objects.

### HOW HVAC WORKS. How HVAC. Works PAGE 1

How HVAC Works PAGE 1 Heat - What is it? Heat is more than a physical concept - it is a feeling. Heat is taught to us at a very young age as a danger to be avoided. Yet, have you ever stopped and thought

### Recrystallization II 23

Recrystallization II 23 Chem 355 Jasperse RECRYSTALLIZATIN-Week 2 1. Mixed Recrystallization of Acetanilide 2. Mixed Recrystallization of Dibenzylacetone 3. Recrystallization of an Unknown Background Review:

### Georgia Performance Standards Framework for Natural Disasters 6 th Grade

The following instructional plan is part of a GaDOE collection of Unit Frameworks, Performance Tasks, examples of Student Work, and Teacher Commentary. Many more GaDOE approved instructional plans are

### Topic Page Contents Page

Heat energy (11-16) Contents Topic Page Contents Page Heat energy and temperature 3 Latent heat energy 15 Interesting temperatures 4 Conduction of heat energy 16 A cooling curve 5 Convection 17 Expansion

### Clouds, Fog, & Precipitation

firecatching.blogspot.com Kids.brittanica.com Clouds and fog are physically the same just location is different Fog is considered a stratus cloud at or near the surface What does one see when looking at

### Taking Apart the Pieces

Lab 4 Taking Apart the Pieces How does starting your morning out right relate to relief from a headache? I t is a lazy Saturday morning and you ve just awakened to your favorite cereal Morning Trails and

### Bay Area Scientists in Schools Presentation Plan

Bay Area Scientists in Schools Presentation Plan Lesson Name Presenter(s) Clouds Everywhere Kristi Closser and Tara Yacovitch Grade Level 5 th Standards Connection(s) Earth science (cloud formation, air

### Dew Point Tester. Instruction Manual. CVS Regular Chiller Model A-2. CVS Regular Chiller Model A-2

Instruction Manual Dew Point Tester The CVS Dew Point Tester is a chilled mirror apparatus, which operates by attaining the conditions necessary by the definition of dew point. When a gas is cooled out

### A H M 531 Penetration & Ring & Ball & Ductility & Flash & Fire point By: Mu'men Al-Otoom

The Civil Engineering Center 1 Visit www.ahm531.com for more lecture notes and E-book! The Civil Engineering Center 2 Visit www.ahm531.com for more lecture notes and E-book! Introduction : The grades of

### Experiment 13: Determination of Molecular Weight by Freezing Point Depression

1 Experiment 13: Determination of Molecular Weight by Freezing Point Depression Objective: In this experiment, you will determine the molecular weight of a compound by measuring the freezing point of a

### Refrigeration Basics 101. By: Eric Nelson

Refrigeration Basics 101 By: Eric Nelson Basics Refrigeration is the removal of heat from a material or space, so that it s temperature is lower than that of it s surroundings. When refrigerant absorbs

### FOR SUBSCRIBERS ONLY! - TRIAL PASSWORD USERS MAY NOT REPRODUCE AND DISTRIBUTE PRINTABLE MATERIALS OFF THE SOLPASS WEBSITE!

FOR SUBSCRIBERS ONLY! - TRIAL PASSWORD USERS MAY NOT REPRODUCE AND DISTRIBUTE PRINTABLE MATERIALS OFF THE SOLPASS WEBSITE! 1 NAME DATE GRADE 5 SCIENCE SOL REVIEW WEATHER LABEL the 3 stages of the water

### It's Cool: The Shape of Change

It's Cool: The hape of Change The text of Lesson 4: It's Cool From the books The hape of Change and The hape of Change: tocks and Flows By Rob Quaden and Alan Ticotsky With Debra Lyneis Illustrated by

### Automobile Air Conditioning Primer

Automobile Air Conditioning Primer An air conditioner is basically a refrigerator without the insulated box. It uses the evaporation of a refrigerant, like Freon, to provide cooling. The mechanics of the

### SOLAR-SYSTEM TOUR QUESTIONS

SOLAR-SYSTEM DATA Name 1. Record the planets and other solar-system objects in order, starting with the Sun. Use the table on the left side of this sheet. If a planet has a moon, write its name in the

### We will try to get familiar with a heat pump, and try to determine its performance coefficient under different circumstances.

C4. Heat Pump I. OBJECTIVE OF THE EXPERIMENT We will try to get familiar with a heat pump, and try to determine its performance coefficient under different circumstances. II. INTRODUCTION II.1. Thermodynamic

### Rusty Walker, Corporate Trainer Hill PHOENIX

Refrigeration 101 Rusty Walker, Corporate Trainer Hill PHOENIX Compressor Basic Refrigeration Cycle Evaporator Condenser / Receiver Expansion Device Vapor Compression Cycle Cooling by the removal of heat

### Chapter 4: Transfer of Thermal Energy

Chapter 4: Transfer of Thermal Energy Goals of Period 4 Section 4.1: To define temperature and thermal energy Section 4.2: To discuss three methods of thermal energy transfer. Section 4.3: To describe

### Fundamentals of Climate Change (PCC 587): Water Vapor

Fundamentals of Climate Change (PCC 587): Water Vapor DARGAN M. W. FRIERSON UNIVERSITY OF WASHINGTON, DEPARTMENT OF ATMOSPHERIC SCIENCES DAY 2: 9/30/13 Water Water is a remarkable molecule Water vapor

### Energy Content of Fuels

Experiment 9 Energy content is an important property of fuels. This property helps scientists and engineers determine the usefulness of a fuel. Energy content is the amount of heat produced by the burning

### WHAT HAPPENS TO WATER ABSORBENT MATERIALS BELOW ZERO DEGREES?

WHAT HAPPENS TO WATER ABSORBENT MATERIALS BELOW ZERO DEGREES? Relative humidity (RH) below zero is defined as the actual water vapour pressure in the air (or space) divided by the saturation vapour pressure

### Heat and Temperature: Front End Evaluation Report. Joshua Gutwill. October 1999

Heat and Temperature: Front End Evaluation Report Joshua Gutwill October 1999 Keywords: 1 Heat and Temperature Front End Evaluation Report October 28, 1999 Goal:

### Temperature. Temperature

Chapter 8 Temperature Temperature a number that corresponds to the warmth or coldness of an object measured by a thermometer is a per-particle property no upper limit definite limit on lower end Temperature

### Chapter 13 - LIQUIDS AND SOLIDS

Chapter 13 - LIQUIDS AND SOLIDS Problems to try at end of chapter: Answers in Appendix I: 1,3,5,7b,9b,15,17,23,25,29,31,33,45,49,51,53,61 13.1 Properties of Liquids 1. Liquids take the shape of their container,

### = 1.038 atm. 760 mm Hg. = 0.989 atm. d. 767 torr = 767 mm Hg. = 1.01 atm

Chapter 13 Gases 1. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. Gases have volumes that depend on their conditions, and can be compressed or expanded by

### Why hot water freezes faster than cold water

Why hot water freezes faster than cold water By Daniel Muthukrishna Undergraduate Engineering/Physics Student at the University of Queensland Images also produced by Daniel Muthukrishna Some of the main

### Geothermal Energy Using Water-Source Heat Pumps

Geothermal Energy Using Water-Source Heat Pumps By VIRSTAR Corporation Geothermal Expertise Since 1978 All information contained herein is the exclusive property of VIRSTAR Corporation, all rights reserved.

### Experiment 3: Extraction: Separation of an Acidic, a Basic and a Neutral Substance

1 Experiment 3: Extraction: Separation of an Acidic, a Basic and a Neutral Substance Read pp 142-155, 161-162, Chapter 10 and pp 163-173, Chapter 11, in LTOC. View the videos: 4.2 Extraction (Macroscale);

### Section 15.2 Water Purification

Section 15.2 Water Purification Fresh water is an essential ingredient of modern life. Thought it s often available as the result of natural processes, there are times when it must be extracted from impure

### Fog and Cloud Development. Bows and Flows of Angel Hair

Fog and Cloud Development Bows and Flows of Angel Hair 1 Ch. 5: Condensation Achieving Saturation Evaporation Cooling of Air Adiabatic and Diabatic Processes Lapse Rates Condensation Condensation Nuclei

### Method 202 Dry Impinger Method for Determining Condensable Particulate Emissions from Stationary Sources. By: Paul Ottenstein

Air Quality Issues in the Rocky Mountain Region PM2.5 Source Testing Method 201A Determination PM 10 and PM 2.5 Emissions from Stationary Sources (Constant Sampling Rate Procedure) Method 202 Dry Impinger

### A discussion of condensate removal systems for clarifier and thickener drives for water and wastewater facilities.

A discussion of condensate removal systems for clarifier and thickener drives for water and wastewater facilities. Richard L. Dornfeld, BSME, P.E. Staff Engineer September 25, 2014 Moisture can be a problem

### Chapter 3. Thermal Energy

Chapter 3 Thermal Energy In order to apply energy conservation to a falling ball or a roller coaster in the previous chapter, we had to assume that friction (with the air or the track) was negligible.

### Clouds, Clouds, Everywhere

1 Clouds, Clouds, Everywhere Grade Level 1 st Grade_ Standards Connection(s): Earth Science: Weather can be observed, measured, and described. Physical Science: States of Materials. Solids, liquids, gases

### Natural Gas Information Contents

Natural Gas Information Contents What is natural gas Natural Gas Components Physical Properties of Natural Gas Different Forms of Natural Gas The Use of Natural Gas Co-generation System Natural Gas and

### How much do you know about HVAC? Try testing yourself with the following questions and then take a look at the answers on the following page.

Demystifying HVAC Test Your HVAC Knowledge By Ron Prager How much do you know about HVAC? Try testing yourself with the following questions and then take a look at the answers on the following page. 1)

### Troubleshooting HVAC/R systems using refrigerant superheat and subcooling

Troubleshooting HVAC/R systems using refrigerant superheat and subcooling Application Note Troubleshooting and servicing refrigeration and air conditioning systems can be a challenging process for both

### Lesson 1 HVAC/R TECHNOLOGY

HVAC/R TECHNOLOGY As you read in the introduction to this course, HVAC/R technicians are known for performing a very broad range of tasks on a variety of equipment. Their work most often requires working

### AIRFREE TECHNIQUE AND SENSITIVE REAGENTS S ECTI O N 1: GLASS W ARE A ND E Q UIP M ENT. A. Using a manifold

AIRFREE TECHNIQUE AND SENSITIVE REAGENTS S ECTI O N 1: GLASS W ARE A ND E Q UIP M ENT Some organic compounds are air sensitive. They can react with the water vapor or oxygen in the air. In order to perform

### In the compression-refrigeration loop (air conditioning), which is likely to be warmer? 1. Condenser coil 2. Evaporator coil

In the compression-refrigeration loop (air conditioning), which is likely to be warmer? 1. Condenser coil 2. Evaporator coil Answer: (1) Condenser coil See the video. A.R.E. Building Systems Study Guide

### Precipitation forms from water droplets or ice crystals.

KEY CONCEPT Water falls to Earth s surface as precipitation. BEFORE, you learned Water moves between Earth's surface and the atmosphere Water vapor condenses into clouds NOW, you will learn How precipitation

### LYRASIS DISASTER RECOVERY REQUEST FOR QUALIFICATIONS

LYRASIS DISASTER RECOVERY REQUEST FOR QUALIFICATIONS Completed qualifications may be sent to Robin Dale (robin.dale@lyrasis.org) Director, Digital and Preservation Services 1438 West Peachtree Street,

### Mpemba effect from a viewpoint of an experimental physical chemist. by Nikola Bregović

Mpemba effect from a viewpoint of an experimental physical chemist by Nikola Bregović Introduction Checking my email a few weeks ago, I found a message from my close friend with the title This seams like

### SECTION 5 COMMERCIAL REFRIGERATION UNIT 21 EVAPORATORS AND THE REFRIGERATION SYSTEM

SECTION 5 COMMERCIAL REFRIGERATION UNIT 21 EVAPORATORS AND THE REFRIGERATION SYSTEM UNIT OBJECTIVES After studying this unit, the reader should be able to Define high-, medium-, and low-temperature refrigeration.

### How air conditioning works

1 How air conditioning works The essential ingredients in an air conditioning system are a fan to blow air around, a cold surface to cool and dehumidify the air, a warm surface and a source of water vapour.

### Things you need. Time ?????? Large pyrex beaker preferably 500 to 1000ml, or large steel vacuum

This experiment is a means of observing the effect of cold temperatures on a range of everyday items. A freezing solution is made for this purpose by adding dry ice to a pure alcohol. This is strictly

### Analyze Weather in Cold Regions and Mountainous Terrain

Analyze Weather in Cold Regions and Mountainous Terrain Terminal Learning Objective Action: Analyze weather of cold regions and mountainous terrain Condition: Given a training mission that involves a specified

### National Aeronautics and Space Administration. The Sun. Water Cycle. and The. www.nasa.gov

National Aeronautics and Space Administration The Sun and The Water Cycle Written by Wendy M. Van Norden illustrated by autumn haac www.nasa.gov The Sun and The Water Cycle Written by Wendy M. Van Norden

### Physical Chemistry Practical Course, Oxford University. Determination of the Surface Area of Alumina by Nitrogen Adsorption at 77K (4 points)

Physical Chemistry Practical Course, Oxford University 1.06 Determination of the Surface Area of Alumina by Nitrogen Adsorption at 77K (4 points) What you will do In this experiment you will study the

### Characteristics of Evaporators

Characteristics of Evaporators Roger D. Holder, CM, MSME 10-28-2003 Heat or Energy In this paper, we will discuss the characteristics of an evaporator coil. The variance of the operational condenses of

### Thermal Storage Unit Using the Triple Point of Hydrogen

Storage Unit Using the Triple Point of Hydrogen I. Charles 1, A. Coynel 1, C. Daniel 2 1 CEA/DSM/INAC/SBT, 38 054 Grenoble Cedex 09, France 2 CNES, Toulouse, 31055 Cedex 4, France ABSTRACT The French space

### Nonrenewable Natural Gas. Natural Gas Basics. How Was Natural Gas Formed?

Did You Know? Because natural gas is colorless, odorless, and tasteless, mercaptan (a chemical that smells like sulfur) is added before distribution, to give it a distinct unpleasant odor (it smells like

### The Importance of Understanding Clouds

NASA Facts National Aeronautics and Space Administration www.nasa.gov The Importance of Understanding Clouds One of the most interesting features of Earth, as seen from space, is the ever-changing distribution

### Chapter 4, Lesson 4: Energy Levels, Electrons, and Covalent Bonding

Chapter 4, Lesson 4: Energy Levels, Electrons, and Covalent Bonding Key Concepts The electrons on the outermost energy level of the atom are called valence electrons. The valence electrons are involved

### [7] SD3.1 The student demonstrates an understanding of cycles influenced by energy from the

Cloud Types Levels Overview: During this project, students learn about different types of clouds and determine which type of cloud is most commonly overhead in their area over a period of four weeks. Objectives:

### THE SOLAR SYSTEM - EXERCISES 1

THE SOLAR SYSTEM - EXERCISES 1 THE SUN AND THE SOLAR SYSTEM Name the planets in their order from the sun. 1 2 3 4 5 6 7 8 The asteroid belt is between and Which planet has the most moons? About how many?

### UNIT 2 REFRIGERATION CYCLE

UNIT 2 REFRIGERATION CYCLE Refrigeration Cycle Structure 2. Introduction Objectives 2.2 Vapour Compression Cycle 2.2. Simple Vapour Compression Refrigeration Cycle 2.2.2 Theoretical Vapour Compression

### Chillin Out: Designing an Insulator

SHPE Jr. Chapter May 2015 STEM Activity Instructor Resource Chillin Out: Designing an Insulator Students learn about the three ways heat can be transferred from one object to another. They also learn what

### Chapter 8, Part 1. How do droplets grow larger? Cloud Droplets in Equilibrium. Precipitation Processes

Chapter 8, Part 1 Precipitation Processes How do droplets grow larger? Cloud contain water droplets, but a cloudy sky does not always mean rain. Cloud Droplets in Equilibrium In equilibrium water molecules

### Heat. Chapter 4. 1. What is the difference between heat and temperature? 2. Why does an ice cube melt in your hand?

Chapter 4 Heat Have you ever seen a hot air balloon float high above Earth s surface? What about a hang glider or a soaring bird of prey like a hawk? Each of these objects a hot air balloon, a hang glider,

### Glaciogenic Cloud Seeding to Increase Orographic Precipitation Bruce A. Boe bboe@weathermod.com Director of Meteorology

Glaciogenic Cloud Seeding to Increase Orographic Precipitation Bruce A. Boe bboe@weathermod.com Director of Meteorology Weather Modification, Inc. Fargo, North Dakota, USA www.weathermodification.com Content

### A brief explanation on how air conditioning works and what terms mean

A brief explanation on how air conditioning works and what terms mean -presented by- Before we begin, let s explain the air conditioning process. In the most basic of terms, air conditioning simply takes

### Energy - Heat, Light, and Sound

Science Benchmark: 06:06 Heat, light, and sound are all forms of energy. Heat can be transferred by radiation, conduction and convection. Visible light can be produced, reflected, refracted, and separated

### This chapter discusses: 1. Definitions and causes of stable and unstable atmospheric air. 2. Processes that cause instability and cloud development

Stability & Cloud Development This chapter discusses: 1. Definitions and causes of stable and unstable atmospheric air 2. Processes that cause instability and cloud development Stability & Movement A rock,

### Sugar or Salt? Ionic and Covalent Bonds

Lab 11 Sugar or Salt? Ionic and Covalent Bonds TN Standard 2.1: The student will investigate chemical bonding. Have you ever accidentally used salt instead of sugar? D rinking tea that has been sweetened

### COURSE TITLE : REFRIGERATION AND AIR CONDITIONING COURSE CODE : 4029 COURSECATEGORY : A PERIODS/WEEK : 5 PERIODS/SEMESTER : 90 CREDITS : 4 OBJECTIVES

COURSE TITLE : REFRIGERATION AND AIR CONDITIONING COURSE CODE : 4029 COURSECATEGORY : A PERIODS/WEEK : 5 PERIODS/SEMESTER : 90 CREDITS : 4 TIME SCHEDULE MODULE TOPICS PERIODS 1 Introduction 22 Principles

### Scholars Research Library

Available online at www.scholarsresearchlibrary.com Scholars Research Library Archives of Physics Research, 2010, 1 (2):103-111 (http://scholarsresearchlibrary.com/archive.html) ISSN 0976-0970 Lubricating

### Evaluation copy. Figure 1

O 2 Extraction by the Lungs Computer 23 Oxygen is required for cell metabolism. During inhalation air is brought into the lungs, where oxygen is extracted. Oxygen passes into the bloodstream at the membrane

### ATOMS AND BONDS. Bonds

ATOMS AND BONDS Atoms of elements are the simplest units of organization in the natural world. Atoms consist of protons (positive charge), neutrons (neutral charge) and electrons (negative charge). The

### Identification and Prevention of Frost or Freeze Damage By Linda Reddick, Kingman Area Master Gardener

KINGMAN IS GROWING! COLUMN Identification and Prevention of Frost or Freeze Damage By Linda Reddick, Kingman Area Master Gardener Again this year we have been experiencing some very cold weather, with

### WILLIAM C. WHITMAN WILLIAM M. JOHNSON JOHN A. TOMCZYK EUGENE SILBERSTEIN

Licensed to: CengageBrain User 2 5 T H A N N I V E R S A R Y REFRIGERATION & AIR CONDITIONING TECHNOLOGY SEVENTH EDITION WILLIAM C. WHITMAN WILLIAM M. JOHNSON JOHN A. TOMCZYK EUGENE SILBERSTEIN Australia

### Activity: Clouds, Air Pressure and Temperature

Activity: Clouds, Air Pressure and Temperature Materials A clean, clear, dry plastic 2-liter or larger beverage bottle with cap, thin liquid crystal temperature strip (available in aquarium supply stores),

### Heavy-Duty Air Conditioning And Heater Service

A i r C o n d i t i o n i n g S y s t e m Red Dot HVAC Training Manual Heavy-Duty Air Conditioning And Heater Service Heavy Duty Air Conditioning and Heating Service Training Manual Go to Table of Contents

### Optimum Solar Orientation: Miami, Florida

Optimum Solar Orientation: Miami, Florida The orientation of architecture in relation to the sun is likely the most significant connection that we can make to place in regards to energy efficiency. In

### WORKSHEET: ph and Water 23 Lab Instructor: Lab Day & Time: Student name(s): drain cleaner flat soda pop window cleaner ammonia.

WORKSHEET: ph and Water 23 Lab Instructor: Lab Day & Time: Student name(s): DATA AND ANALYSIS ph Substance ph Value Substance ph Value Substance ph Value pure water apple juice dish soap sugar water beer

### SERVICE MANUAL. Room Air Conditioner Multi Split Wall-Mounted Type Indoor. FSAI-Pro-91AE2 FSAI-Pro-121AE2 FSAIF-Pro-181AE2

SERVICE MANUAL Room Air Conditioner Multi Split Wall-Mounted Type Indoor FSAI-Pro-91AE2 FSAI-Pro-121AE2 FSAIF-Pro-181AE2 NOTE: Before servicing the unit, please read this at first. Always contact with

### HVAC-02, Air Conditioning Troubleshooting and Repair

HVAC-02, Air Conditioning Troubleshooting and Introduction Since I'm constantly receiving questions on 944 air conditioning systems, I figured it's time to come up with come helpful troubleshooting tips.

### Multiple Choice Identify the choice that best completes the statement or answers the question.

Test 2 f14 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Carbon cycles through the Earth system. During photosynthesis, carbon is a. released from wood

### SWIMMING POOL HEAT PUMP

SWIMMING POOL HEAT PUMP Installation & User Manual Model HP40B HP50B HP65B Hayward Pool Products Canada, Inc. T: 1-888-238-7665 www.haywardpool.ca CONTENT I. Application 4 II. Features 4 III. Technical

### ORGANIC LABORATORY TECHNIQUES 10 10.1. NEVER distill the distillation flask to dryness as there is a risk of explosion and fire.

ORGANIC LABORATORY TECHNIQUES 10 10.1 DISTILLATION NEVER distill the distillation flask to dryness as there is a risk of explosion and fire. The most common methods of distillation are simple distillation

### Energy & Conservation of Energy. Energy & Radiation, Part I. Monday AM, Explain: Energy. Thomas Birner, ATS, CSU

Monday AM, Explain: Energy MONDAY: energy in and energy out on a global scale Energy & Conservation of Energy Energy & Radiation, Part I Energy concepts: What is energy? Conservation of energy: Can energy

### CHAPTER 10: INTERMOLECULAR FORCES: THE UNIQUENESS OF WATER Problems: 10.2, 10.6,10.15-10.33, 10.35-10.40, 10.56-10.60, 10.101-10.

CHAPTER 10: INTERMOLECULAR FORCES: THE UNIQUENESS OF WATER Problems: 10.2, 10.6,10.15-10.33, 10.35-10.40, 10.56-10.60, 10.101-10.102 10.1 INTERACTIONS BETWEEN IONS Ion-ion Interactions and Lattice Energy

### Clouds. A simple scientific explanation for the weather-curious. By Kira R. Erickson

Clouds A simple scientific explanation for the weather-curious By Kira R. Erickson Table of Contents 1 3 4 INTRO 2 Page 3 How Clouds Are Formed Types of Clouds Clouds and Weather More Information Page

### RESULTS OF ICARUS 9 EXPERIMENTS RUN AT IMRA EUROPE

Roulette, T., J. Roulette, and S. Pons. Results of ICARUS 9 Experiments Run at IMRA Europe. in Sixth International Conference on Cold Fusion, Progress in New Hydrogen Energy. 1996. Lake Toya, Hokkaido,

### SECTION 5 COMMERCIAL REFRIGERATION UNIT 22 CONDENSERS

SECTION 5 COMMERCIAL REFRIGERATION UNIT 22 CONDENSERS UNIT OBJECTIVES After studying this unit, the reader should be able to explain the purpose of the condenser in a refrigeration system. describe differences

### Pure Solid Compounds: Molecules held together in rigid formations by intermolecular forces.

Recrystallization: Purification of Solid Compounds Pure Solid Compounds: Molecules held together in rigid formations by intermolecular forces. Types of Intermolecular Forces? 1. Van der Waal s forces London

### RELEASED. Student Booklet. Chemistry. Fall 2014 NC Final Exam. Released Items

Released Items Public Schools of North arolina State oard of Education epartment of Public Instruction Raleigh, North arolina 27699-6314 Fall 2014 N Final Exam hemistry Student ooklet opyright 2014 by

### Liquids are all around us. Every day we drink and eat items that contain liquids, we use liquids to

Excellent Evaporation Science Fair Research Paper By: Suzie Science Class December 16, 2008 Background Information Liquids are all around us. Every day we drink and eat items that contain liquids, we use