# Episode 608: Latent heat

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Episode 608: Latent heat Energy is involved in changes of phase, even though there is no change of temperature. Summary Discussion: Defining specific latent heat. (10 minutes) Demonstration: Boiling water. (15 minutes) Student experiment: Measuring l. (30 minutes) Student experiment: Cooling curves. (30 minutes) Worked example: Latent and specific heat (5 minutes) Student questions: Involving c and l. (40 minutes) Discussion: Defining specific latent heat The final point in this topic is to return to the original definition of internal energy as being both kinetic and potential. In talking about ideal gases all the energy was kinetic because there were assumed to be no bonds between the atoms. However, in a solid or liquid there are bonds and clearly some energy is needed to break those bonds. That means that, in melting a solid or boiling a liquid, a substantial amount more energy needs to be added which does not raise the temperature. This is the latent ( hidden ) heat. The energy required to melt a mass m of a substance is given by ΔE = ml. Or the specific latent heat is the energy required to change the unit mass from one phase to another. (resourcefulphysics.org) Demonstration: Boiling water Ask your class to watch some water boiling and think about what is going on. Energy is being supplied, but the temperature is not rising. The energy is breaking intermolecular bonds, or, as a physicist would say, work is being done to separate the particles against intermolecular attractive forces. The key point from these is that, for certain materials, there is a phase transition where the heat energy no longer raises the temperature (kinetic energy per molecule) but instead breaks bonds and separates the particles (potential energy). This should be made quantitative. Likewise, the reverse processes involve energy being given up from the substance. So evaporating liquids are good coolants and freezing water to make ice is considerably more of an effort than cooling water to 0 C. TAP 608-1: Examination of boiling 1

2 Student experiment: Measuring L It is useful to have measured a specific latent heat for example, that of melting ice. TAP 608-2: The specific latent heat of fusion of ice Student experiment: Cooling curves If you have a class set of data-loggers for recording temperature, determination of the cooling curve of stearic acid, naphthalene or lauric acid is worthwhile. Even as a demonstration this is good and can be left running in the background while the students work on calculations. TAP 608-3: Heating and cooling curves Worked example: Latent and specific heat Scalds from water and steam We assume that our hand is at 37 o C, and that we put 10 g of water at 100 o C accidentally on our hand. The water will cool to 37 o C. Assuming that all the heat energy "lost" by the water will be gained by our hand: Heat "lost" by water = m c Δθ = 0.01 x 4200 x 63 =2,646 J. But if the 10 g had been steam then the steam would first have to condense. Heat "lost" in condensing = ml = 0.01 x = 22,600 J So the heat lost in 10 g of steam turning to water at 37 o C is 22, ,646 = 25,246 J. This is nearly ten times as much as the water alone! The worked example is based on one from Resourceful Physics Student questions: Involving c and l Practice in situations involving specific heat capacity and specific latent heat. TAP 608-4: Questions involving specific heat capacity and specific latent heat 2

3 TAP 608-5: Further specific and latent heat questions 3

4 TAP 608-1: Examination of boiling Class experiment This is a magnificent experiment which at the outset may not appear very exciting. You will need For each student group Bunsen burner Pyrex beaker Tripod, gauze and heat-resistant mat Thermometer -10 C to 110 C Safety Students must not sit down to watch this experiment - serious scalding has occurred when the beaker breaks or falls and the pupil has been unable to move away instantly. What to do 1. Half fill a beaker with water and then bring it gently to the boil. 2. Watch the process carefully, observing the formation of bubbles. 3. Write down your observations. Question What tells you water is boiling? 4

5 Practical advice 1. This experiment could begin with a block of ice in the beaker which is allowed to melt. 2. Students see small bubbles forming from dissolved air, but when boiling starts there is a quite different situation due to the formation of water vapour (steam) in bubbles. 3. Students are apt to have very careless views of the essential nature of boiling. E.g.: (i) (ii) A fixed (!) boiling point that depends on the vapour at atmospheric pressure pushing the outer air away (when in fact vapour molecules diffuse through air easily) A vague story of more copious evaporation with no clear reason for the constancy of boiling temperature. Ask "what tells you water is boiling? and insist on the clear answer, bubbles of water vapour. 4. Bubbles cannot form and grow in the liquid until the vapour pressure in them matches the outside atmospheric pressure. The liquid boils away as fast as heating provides the exittax of latent heat. Once the liquid is boiling, further heating simply equips more molecules with enough motion energy to evaporate into vapour bubbles. Therefore, the temperature stays constant at the boiling point. Thus, evaporation acts as a thermostat for a boiling liquid. (The energy needed to pay the exittax makes distillation an expensive business.) 5. Let students carry out the experiment the first time without a thermometer in the water. A very able group could plot temperature-time graphs. Safety Students must not sit down to watch this experiment - serious scalding has occurred when the beaker breaks or falls and the pupil has been unable to move away instantly. External references This activity is taken from Resourceful Physics 5

6 TAP 608-2: The latent heat of fusion of ice This experiment is designed to measure the amount of heat needed to turn 1 kg of ice at 0 o C into 1 kg of water at 0 o C You will need electric immersion heater (12 V, 60 W) funnel glass beaker ac ammeter ac voltmeter power supply (12 V ac, 6 A) stop clock retort stand, boss and clamp ice balance 12V ac control ICE ICE melted ice What to do Set up the apparatus as shown in the diagram but without the ice. One heater should be connected to the power supply. The other is a control that is set up at the front of the lab. Do not switch on yet. Weigh your beakers. Crush the ice and put the same in each funnel trying to pack it closely round the heater. Start the stopwatch and at the same time switch on the heater, adjusting the voltage to about 12 V. Record the voltage (V) and the current (I). Leave the heater on for three minutes, adding more ice if needed to keep some in contact with the heater. Switch off, remove the beaker and weigh it. 6

7 Observations and calculations Mass of beaker = kg Mass of beaker + melted ice = kg Mass of melted ice = kg Mass of control beaker = kg Mass of control beaker + melted ice = kg Mass of control melted ice = kg Mass of ice melted due the heater alone = kg Heater power (VI) = W Time = s Energy input = Power x Time = J This energy melted kg of ice. So J would melt 1 kg of ice. This is the specific latent heat of fusion of ice. The amount of heat needed to change 1 kg of solid to 1 kg of liquid at its melting point is called the specific latent heat of fusion of the material 7

8 External reference This activity is taken from Resourceful Physics 8

9 TAP 608-3: Heating and cooling curves Stearic acid or lauric acid is heated beyond its melting point and then cooled. You will need test tube test tube holder 15 g stearic acid or lauric acid (there are many suitable substances, see CLEAPSS Hazcard 46, Hydrocarbons (Aromatic)) beakers (400 or 600 cm 3 ) hotplate or careful use of a Bunsen burner 2 thermometers stop clock safety goggles graph paper paper towel Alternative experiment temperature sensor and computer 9

10 What to do Cooling curve 1. Fill one beaker about ⅔ full of warm tap water and place on the hot plate. Adjust the hot plate so that you can maintain the temperature of the water at about 75 o C for stearic acid or 60 o C for lauric acid 2. Fill the other beaker about ⅔ full of water from the tap and set aside. 3. Place the test tube of stearic acid or lauric acid in the hot water on the hot plate. As the acid starts to melt carefully put a thermometer in the test tube. Heat the lauric acid in the 60 o C water until it is at about 55 o C or the stearic acid to 75 o C 4. Put the test tube of liquid stearic or lauric acid tube in the beaker of 30 o C water and record the lauric acid temperature at 30-second intervals until the temperature reaches about 65 o C if using stearic acid or 40 o C for lauric acid. Gently stir with the thermometer as you take data until the acid starts to solidify. You have now completed the cooling curve data. Heating Curve 1. Check that the water bath on the hotplate is still at the correct temperature. Adjust the hot plate if necessary and transfer the stearic or lauric acid tube with the thermometer back into the warm water. 2. Record the temperature of the stearic or lauric acid at 30-second intervals until the temperature reaches about 75 o C (stearic acid), or 50 o C (lauric acid). As soon as it is melted enough, stir the acid with the thermometer. 3. Now remove the thermometer from the acid and thoroughly wipe the acid off with a paper towel. Avoid getting any acid on your skin. Questions 1. What is the melting point of your substance? 2. Explain what is happening in molecular terms for each region of the graphs. 10

11 Practical advice This could be set up with a temperature sensor and computer so the graph is plotted automatically. It is safer to use a hotplate but if a Bunsen is used it should be on a low flame. Stearic acid, CH 3 (CH 2 )16COOH can act as an eye, skin and respiratory irritant so the laboratory should be well ventilated. Melting point o C. Lauric acid C 12 H 24 O 2 or (CH 3 (CH 2 ) 10 COOH), is sometimes called dodecanoic acid or dodecoic acid is a white solid with a melting point of o C. It can act as an eye, skin and respiratory irritant so the laboratory should be well ventilated. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. Naphthalene gives the best curve with sharpest points for onset and completion of solidification. It is rated Harmful but that is no worse than many other substances used in school science. Safety Avoid getting either acid on your skin. Wash off with water for 15 minutes if this occurs. If naphthalene is used, a loose plug of mineral wool in the neck of the tube will minimise the smell. 11

12 TAP 608-4: Questions involving specific heat capacity and specific latent heat Data Specific heat capacity of water = 4200 J kg -1 K -1. Specific heat capacity of iron at 100 C = 220 J kg -1 K -1. Latent heat of vaporisation of water = 2260 kj kg -1. Latent heat of fusion of water = 334 kj kg -1. Density of ice at 0 C is 917 kg m Compare the energy needed to raise the temperature of 1kg of water from 20 C to 100 C and the energy needed to boil 1 kg of water at 100 C. 2. A 5kg block of iron is heated to 800 C. It is placed in a tub containing 2 litre of water at 15 C. Assuming all the water is brought to the boil rapidly; calculate the mass of water which boils off. 3. Sunlight of intensity 0.6 kw m -2 falls on a patch of ice. Assuming the ice absorbs 20% of the light; calculate what thickness of ice would melt in 1 minute. (Assume any water produced runs off). 12

13 Practical advice Pupils may need some guidance. Answers and worked solutions 1. Energy required to heat the water = mcδθ = = 336 kj Energy required to boil the water = ml = kj = 2260kJ. So it takes nearly 7 times as much energy to boil the water as to heat it up. 2. Energy given up by the iron in cooling to 100 C (assuming c is constant) = mcδθ = = 770 kj. To heat 2 litre of water from 15 C to 100 C requires (100-15) = 714 kj. This leaves = 56 kj to boil some of the water. Mass of water boiled away = E/L = 56 / 2260 = kg. 3. In 1 minute = J are absorbed by the ice for each 1 m 2. Let the ice have an area A. The energy absorbed is A. Thickness t will have volume At and will be melted if mass latent heat of fusion = A. The mass of volume At ice is 917At. So A = 917 At t = m or 0.06 mm 13

14 TAP 608-5: Further specific and latent heat questions Data Specific heat capacity of aluminium = 910 J kg -1 K -1. Specific heat capacity of water = 4200 J kg -1 K -1 Specific latent heat of fusion of ice = J kg -1 Specific latent heat of evaporation of water 2.26 MJ kg How much heat energy is needed to heat 4 kg of aluminium by 8 o C? 2. If J of heat energy are given off when a 2 kg block of metal cools by 12 o C, what is the specific heat capacity of the metal? 3. A 50 W heater is used to heat, an aluminium block with a mass of 5 kg. After 10 minutes the temperature of the block has risen by 4 o C. Calculate: (a) the heat given out by the heater; (b) the specific heat capacity of aluminium. (c) Why is your answer different from the correct value given in the data above? 4. How much heat energy is given out when 3 kg of water at 40 o C cool to 25 o C? 14

15 5. How much heat energy is given out when 500 g of steam at 100 o C condenses and then cools to 50 o C? 6. Why is a scald by steam at 100 o C much more painful than one by water at 100 o C? 7. How long will it take a 50 W heater to melt 2 kg of ice at 0 o C? 15

16 Answers and worked solutions 1. Energy = mcδθ = = J 2. Specific heat capacity = energy / (m Δθ) = / (2 12) = 200 J kg -1 K (a) Output energy = power x time = = 30,000 J (b) Specific heat capacity = energy/ (m Δθ) = / (5 4) = 1500 J kg -1 K -1 (c) Heat loss to the surroundings, so the energy retained by the metal is less than 30,000, so the value of C should be lower. 4. Heat energy given out = mcδθ = (40 25) = 189,000 J= 189 kj 5. Energy in condensing =ml = = 1,130,000 J Energy during cooling = mcδθ = = 105,000 J Total energy given out = 1,130, = 1,235,000 J =1,235 kj 6. Because it has to condense first before cooling so giving out a large amount of latent heat. (Better students will give a sample calculation, see the worked example) 7. Power x time = ml so time = ml/power = / 50 = / 50 = s = 223 min = 3.7 hours = 3 hrs 43 minutes (Assumes no heat lost to the surroundings and the water remains at 0 o C.) External reference This activity is taken from Resourceful Physics 16

### Core Lab: Energy Changes During Melting and Evaporation

Science 1206 Name: Core Lab: Energy Changes During Melting and Evaporation Background: When a substance melts, it changes from a solid to a liquid. When a substance evaporates (or vaporizes), it changes

### solvent diffusion dissolving soluble

What do we call it when a liquid changes into a solid? What do we call it when a liquid turns into a gas? What do we call it when a gas turns into a liquid? What do we call the solid that dissolves in

### PHASE CHANGES. Time Temperature Observations. Name(s)

3 5 PHASE CHANGES PHASE CHANGES Name(s) The activities presented here focus on the energy changes that occur in substances undergoing a phase change. The first activity will take the most time to complete.

### Skills in Science. Lab equipment. (Always draw 2D) Drawings below are NOT to scale. Beaker - A general purpose container with a pouring lip.

Skills in Science Safety: Do NOT enter or leave the lab without permission from a teacher. Keep the gaps between tables clear of stools and bags. Never run in the lab. Do not throw things around in the

### 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

### CHEM 1215 LAB NOTES EXPT #2: PHYSICAL AND CHEMICAL CHANGES 1

CHEM 1215 LAB NOTES EXPT #2: PHYSICAL AND CHEMICAL CHANGES 1 TECHNIQUES: chemical and physical changes, reactions, observations READING: PHYSICAL AND CHEMICAL CHANGES e.g. Tro chapter 1 SAFETY: Safety

### Year 7 Chemistry HW Questions

Year 7 Chemistry HW Questions 37 minutes 56 marks Page 1 of 15 Q1. Molly used a ph sensor to test different liquids. She dipped the probe of the sensor into each liquid and recorded the ph value in a table.

### Science Physical Science Grades 6 and 8

Science Physical Science Grades 6 and 8 Subject: Physical Science: Thermal Energy Level: Grade 6 and 8 The Hot in the Cold Abstract: Students will conduct an experiment and collect data on the exchange

### Chem 355 Jasperse DISTILLATION

Chem 355 Jasperse DISTILLATION 1 Background Distillation is a widely used technique for purifying liquids. The basic distillation process involves heating a liquid such that liquid molecules vaporize.

### Chapter 8. Gravimetric Analysis

Chapter 8 Gravimetric Analysis Gravimetric analysis is the use of weighing to determine the amount of a component in your sample. Gravimetric analysis, or gravimetry is normally performed either as a :

### Copper Odyssey. Chemical Reactions of Copper

Name Lab Partner(s) Copper Odyssey Chemical Reactions of Copper Date Period Elemental copper metal will be converted into copper (II) ion and then brought through a series of compound conversions until

### Station 1 Dry Ice Experiments / Producing CO 2 in a reaction

Station 1 Dry Ice Experiments / Producing CO 2 in a reaction 1. WHAT IS DRY ICE Put a flat chunk of dry ice on the counter and see how easy it "floats" on top of the counter when you give it a small push.

### 6. In this temperature time graph for the heating of H 2O at a constant rate, the segment DE represents the

1. Which of the following contains particles with the least freedom of motion? A) CO 2( ) B) HCl(aq) C) F 2(g) D) MgBr 2(s) E) C 6H 12O 6(aq) 2. During boiling, the temperature of a pure liquid substance

### Experimental techniques

Unit 1 Experimental techniques In this unit you will come to understand the general principles behind various experimental techniques. Experimental investigation is a very important aspect of Physical

### Water Temperature Protocol

Water Temperature Protocol Purpose To measure the temperature of a water sample Overview Students use an alcohol-filled thermometer to measure the temperature of water. Student Outcomes Students will learn,

### 2. Crystallization. A. Background

2. Crystallization A. Background Crystallization is one of several available techniques available to purify organic compounds. Unlike other techniques, however, crystallization is specific to the purification

### EXPERIMENT 3: Identification of a Substance by Physical Properties

EXPERIMENT 3: Identification of a Substance by Physical Properties Materials: Hot plate Digital balance Capillary tubes (3) Thermometer Beakers (250 ml) Watch glass Graduated Cylinder (10 ml) Mel-Temp

### The Sense of Smell - Practical work

CONTENTS Extraction of Natural Perfume Ingredients Activity 1 Limonene from citrus fruits Part A: Expression Part B: Steam distillation Part C: Solvent extraction Part D: Determination of yield Part E:

### Name Honors Chemistry / /

Name Honors Chemistry / / SOL Questions Chapter 1 Each of the following questions below appeared on an SOL Chemistry Exam. For each of the following bubble in the correct answer on your scantron. 1. The

### Calculating energy changes from burning fuels

Calculating energy changes from burning fuels TEACHERS AND TECHNICIANS NOTES Specification reference: C3.3.1 Energy from reactions (a) The relative amounts of energy released when substances burn can be

### Copper Smelting by an Ancient Method

Copper Smelting by an Ancient Method EXPERIMENT ## Prepared by Paul C. Smithson, Berea College, based on Yee et al., 004 Using beads of a copper-containing mineral, students will produce beads of nearly

### Porosity of Compost Water retention capacity of Compost Organic matter content of Compost Buffering capacity of Compost

Porosity of Compost Water retention capacity of Compost Organic matter content of Compost Buffering capacity of Compost by Page 1/21 Contents What is the effect of compost on soil properties?... 3 Introduction:...

### Compact Electro Plating Machine - CEPM-2A USER MANUAL

1 Compact Electro Plating Machine - CEPM-2A USER MANUAL PRODUCT INTRODUCTION: This compact electroplating machine is a high performance compact plating unit that is especially designed for coating all

### Recrystallization with a Single Solvent

Experiment: Recrystallization Part II: Purification of Solids In Part I of the recrystallization experiment, you learned about the factors which make a good recrystallization solvent, and you learned how

### Eutrophication Using Up Oxygen In Water

Eutrophication Using Up Oxygen In Water Topic Water pollution causing oxygen depletion in water by living organisms Introduction Farming is a major cause of freshwater pollution. Sewage and farm animal

### Lab 1 Basics of Energy Production I

1 Lab 1 Basics of Energy Production I Relevant SOLs: PS.1a, PS.1b, PS.1d, PS.1k, PS.1m, PS.2e, PS.2f, PS.5a, PS.5c, PS.6a, PS.6b, PS.6c, PS.7a, PS.7b, PS.9c, 3.1h, 3.1j, 3.11a, 3.11b, 4.3d, 5.3a, 5.4c,

### Evaluation copy. Total Dissolved Solids. Computer INTRODUCTION

Total Dissolved Solids Computer 12 INTRODUCTION Solids are found in streams in two forms, suspended and dissolved. Suspended solids include silt, stirred-up bottom sediment, decaying plant matter, or sewage-treatment

### Electricity. Characteristic and efficiency of PEM fuel cell and PEM electrolyser Stationary currents. What you need:

Stationary currents Electricity Characteristic and efficiency of PEM fuel cell and PEM electrolyser What you can learn about Electrolysis Electrode polarisation Decomposition voltage Galvanic elements

### Electrolysis, electrode polarisation, decomposition voltage, galvanic elements, Faraday s law.

Characteristics and efficiency of PEM fuel cell TEP Related Topics Electrolysis, electrode polarisation, decomposition voltage, galvanic elements, Faraday s law. Principle In a PEM electrolyser, the electrolyte

### Heat and Thermal Energy

Next Generation Science Standards NGSS Science and Engineering Practices: Asking questions and defining problems Developing and using models Planning and carrying out investigations Analyzing and interpreting

### EXPERIMENT 1 SOLID LIQUID PHASE DIAGRAM

EXPERIMENT 1 SOLID LIQUID PHASE DIAGRAM Important: bring a formatted 3.5 floppy diskette/usb flash drive for this laboratory you will need it to save your data files! Introduction The relation of cooling

### Characteristic and efficiency of PEM fuel cell and PEM electrolyser

Related topics Electrolysis, electrode polarisation, decomposition voltage, galvanic elements, Faraday s law. Principle and task In a PEM electrolyser, the electrolyte consists of a protonconducting membrane

### GRAVIMETRIC DETERMINATION OF SULFATE IN AN UNKNOWN SOLUTION

GRAVIMETRIC DETERMINATION OF SULFATE IN AN UNKNOWN SOLUTION AIM The main objective of this experiment is to determine the concentration of sulfate ion in an unknown solution by using gravimetry. INTRODUCTION

### IDENTIFYING UNKNOWN SUBSTANCES

IDENTIFYING UNKNOWN SUBSTANCES LAB 15 EXPERIMENT STUDENT BOOK Chapter 1, page 25 TOOLBOX Page 4 and 36 Goal Identify unknown substances with the help of different tests. 1. What is the independent variable

### 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:

### CH 149: Chemical Principles. Fall KP1019 Module TA Manual

CH 149: Chemical Principles Fall 2012 KP1019 Module TA Manual 2 Table of Contents KP1019 Synthesis 3 ORP Titrations...10 Electrochemistry 15 ph Kinetics 19 Temperature/NaCl Kinetics...24 3 Equipment (per

### To whom it may concern, February 21, 2011

To whom it may concern, February 21, 2011 The following is an evaluation of the GEMS grant that I received to start my own C-MORE lab kits, specifically ocean acidification, plankton, marine debris and

### Experiment 4 MELTING POINTS OF ORGANIC COMPOUNDS 1

Experiment 4 MELTING POINTS OF ORGANIC COMPOUNDS 1 Background: The melting point of an organic solid is probably the most widely used physical constant. If you want a quick, easy, and cheap way to characterize

### CHEM 254 EXPERIMENT 8. Phase Diagrams, Solid - Liquid Phase Equilibrium for Two Component System and Missibility Gap

Temperature, T Temperature, T CHEM 254 EXPERIMENT 8 Phase Diagrams, Solid - Liquid Phase Equilibrium for Two Component System and Missibility Gap Solid and liquid phases may both be present in a system

### Zinc 17. Part 2 Practical work

Zinc 17 Part 2 Practical work 18 Zinc and Zirconia (per group) Teacher s notes Using carbon to extract copper from copper oxide could be used as an introduction to extracting less-reactive metals by displacement.

### A student investigated the efficiency of a motor using the equipment in Figure 1. Figure 1

A student investigated the efficiency of a motor using the equipment in Figure. Figure He used the motor to lift a weight of 2.5 N a height of 2.0 m. He measured the speed at which the weight was lifted

### hydroxynitrile ester dihaloalkane alkane alkene haloalkane alcohol amine nitrile ketone HCN + KCN Nucleophilic addition carboxylic acid

6.2.5 Synthesis dihaloalkane poly(alkene) high pressure atalyst polymerization Br 2, l 2 Electrophilic addition alkene alkane 2, Nickel atalyst addition/reduction Br 2, l 2 UV light Free radical Substitution

### ) and it s ideal van t Hoff factor is 4. Note that polyatomic ions do not break up into their constituent elements.

Freezing Point Depression: Determining CaCl2 Van t Hoff Factor Minneapolis Community and Technical College C1152 v.12.15 I. Introduction The physical properties of solutions that depend on the number of

### DETERMINATION of the EMPIRICAL FORMULA

DETERMINATION of the EMPIRICAL FORMULA One of the fundamental statements of the atomic theory is that elements combine in simple whole number ratios. This observation gives support to the theory of atoms,

### Energy and Heat S1 Physics Unit 2 Pupil Booklet Wallace Hall Academy

Energy and Heat S1 Physics Unit 2 Pupil Booklet Wallace Hall Academy Types of energy S1 Physics Unit 2 Lesson 1.1 Learning Outcome: I can name several types of energy. I can state the law of conservation

### An Oxidation-Reduction Titration: The Reaction of Fe 2+ and Ce 4+

An Oxidation-Reduction Titration: The Reaction of Fe 2+ and Ce 4+ LAB ADV COMP 8 From Advanced Chemistry with Vernier, Vernier Software & Technology, 2004 INTRODUCTION A titration, as you recall, is a

### Sci-Tech. Connections. The Heat's On. Hot Potatoes Grade 7 Sampler

Sci-Tech Connections The Heat's On Hot Potatoes Grade 7 Sampler HOT POTATOES EXPECTATIONS work cooperatively, respect each other, work safely, and keep a clean work space use the terms heat and cooling

### to the presentation Teaching Thermodynamics: Chemical Potential from the Beginning Regina Rüffler, Georg Job

to the presentation Teaching Thermodynamics: Chemical Potential from the Beginning Regina Rüffler, Georg Job Thermo International 2006 Boulder, August 3, 2006 FOUNDATION Further informations on the homepage:

### What are the 3 ways in which energy can travel? Explain what. conduction is. Does conduction happen best in solids, liquids or gases?

What are the 3 ways in which energy can travel? Explain what conduction is What type of materials are good conductors and what type of materials are bad conductors (good insulators)? Does conduction happen

### LAB 13: HEAT ENGINES AND THE FIRST LAW OF THERMODYNAMICS

Lab 13 Heat Engines and the First Law of Thermodynamics 159 Name Date Partners LAB 13: HEAT ENGINES AND THE FIRST LAW OF THERMODYNAMICS... the quantity of heat produced by the friction of bodies, whether

### The reduction of copper oxide

The reduction of copper oxide Topic Formula determination, extraction of metals. Timing About 10 min. Level Pre-16. Description Copper(II) oxide can be reduced by hydrogen and its formula determined. Natural

### The determination of copper in brass

The determination of copper in brass Objective - To determine the amount of copper in a brass sample Background Brass is an alloy made of copper and zinc. Most brass contains about 60% copper. The proportions

### Melting Point 1. Figure 2. A close-up of the "business end" of the Mel-Temp apparatus. Figure 1. The mel-temp device.

Melting Point 1 The temperature at which a solid melts is known as the melting point (MP) of that substance. The melting point is a physical property of a solid and can be used to help identify a substance.

### TITANIUM DIOXIDE. SYNONYMS Titania; CI Pigment white 6; CI (1975) No ; INS No. 171 DEFINITION DESCRIPTION FUNCTIONAL USES CHARACTERISTICS

TITANIUM DIOXIDE Prepared at the 71 st JECFA (2009) and published in FAO JECFA Monographs 7 (2009), superseding specifications prepared at the 67 th JECFA (2006) and published in FAO JECFA Monographs 3

### Elemental Mass Percent and Empirical Formula From Decomposition of a Copper Oxide

EXPERIMENT Elemental Mass Percent and Empirical Formula From Decomposition 6 Prepared by Edward L. Brown, Lee University and Verrill M. Norwood, Cleveland State Community College The student will heat

### H N 2. Decolorizing carbon O. O Acetanilide

Experiment 1: Recrystallization of Acetanilide Reading Assignment Mohrig 2 4 (Glassware, Reagents, & Heating) & 14 15 (Melting Point & Recrystallization) The purification of organic compounds is a tedious,

### Changes to the Atmosphere

Changes to the Atmosphere 49 minutes 49 marks Page of 24 Q. The amount of carbon dioxide in the Earth s atmosphere has changed since the Earth was formed. The amount of carbon dioxide continues to change

### Experiment: Preparation of Adipic Acid by Oxidative Cleavage of Cyclohexene

Experiment: Preparation of Adipic Acid by xidative Cleavage of Cyclohexene Under mild conditions, only the pi bond of the alkene is cleaved to form 1,2-diols or epoxides. Under more rigorous oxidation

### Soil Particle Density Protocol

Soil Particle Density Protocol Purpose To measure the soil particle density of each horizon in a soil profile Overview Students weigh a sample of dry, sieved soil from a horizon, mix it with distilled

### To identify and classify various types of chemical reactions.

Cycle of Copper Reactions Minneapolis Community and Technical College v.11.17 Objectives: To observe and document copper s chemical changes in five different reactions and verify that copper is conserved

### Total Dissolved Solids

Total Dissolved Solids LabQuest 12 INTRODUCTION Solids are found in streams in two forms, suspended and dissolved. Suspended solids include silt, stirred-up bottom sediment, decaying plant matter, or sewage-treatment

### ENGI Environmental Laboratory. Lab #2. Solids Determination. Faculty of Engineering & Applied Science

ENGI 9628 Environmental Laboratory Lab #2 Solids Determination Faculty of Engineering & Applied Science SOLIDS DETERMINATION PURPOSE Using Standard Methods for solids determination. THEORY Total solids

### Acid Rain and Its Effect on Surface Water. Evaluation copy. Figure 1: Typical rain ph in United States.

Acid Rain and Its Effect on Surface Water Computer 16 Acid rain can be very harmful to the environment. It can kill fish by lowering the ph of lakes and rivers. It can harm trees and plants by burning

### Chemistry Quiz #1 Review

Name: Chemistry Quiz 1 Review Page 1 of 6 Date: Please check your answers at http://leetz.weebly.com Chemistry Quiz #1 Review Part A: Density Calculations 1. The density of sodium is 0.97 g/cm 3. A sample

### Forensics with TI-Nspire Technology

Forensics with TI-Nspire Technology 2013 Texas Instruments Incorporated 1 education.ti.com Science Objectives Identify characteristics of different soils to demonstrate that a suspect has been at a scene.

### EXPERIMENT 9 DEHYDRATION OF 2-METHYLCYCLOHEXANOL CH 3 H CH 3 OH H 3 PO 4 +

EXPERIMENT 9 DEHYDRATION OF 2-METHYLCYCLOHEXANOL CH 3 CH 3 H CH 3 OH H 3 PO 4 + + H 2 O In this experiment, a microscale distillation apparatus will be used to perform an acid-catalyzed dehydration reaction

### CH241 Experiment #1 (Weeks of September 11, 18, and 25, 2017)

CH241 Experiment #1 (Weeks of September 11, 18, and 25, 2017) SEPARATION AND RECOVERY OF ORGANIC COMPOUNDS, THIN LAYER CHROMATOGRAPHY, COLUMN CHROMATOGRAPHY, CRYSTALLIZATION, AND MELTING POINTS Overview

### Chapter 3 - Energy and Matter Practice Problems

Chapter 3 - Energy and Matter Practice Problems 1) Helium is a(n) A) compound. B) heterogeneous mixture. C) element. D) homogeneous mixture. E) electron. 2) Air is a(n) A) compound. B) heterogeneous mixture.

### Experiment 2: The Chromatography of Organic Compounds

Experiment 2: The Chromatography of Organic Compounds INTRODUCTION When performing an organic reaction, it is very common to observe the formation of other compounds in addition to your desired product;

### THERMAL ENERGY STORAGE SYSTEMS STEARIC / LAURIC ACID MIXTURES AS PHASE CHANGE MATERIALS

3.014 MATERIALS LABORATORY MODULE- β1 September 26 30, 2005 GEETHA P. BERERA THERMAL ENERGY STORAGE SYSTEMS STEARIC / LAURIC ACID MIXTURES AS PHASE CHANGE MATERIALS OBJECTIVES: Prepare stearic acid and

### Equation Writing and Predicting Products Chemistry I Acc

Introduction: Equation Writing and Predicting Products Chemistry I Acc If you examine your bicycle after it has been left out in the rain a number of times you will find that it has begun to rust. Rust

### DURNI-COAT DNC

RIAG Oberflächentechnik AG Postfach 169 CH-9545 Wängi TG 25.04.2014 DURNI-COAT DNC 520-12-50 Electroless plating nickel bath for high wear and corrosion resistant applications DNC 520-12-50 is a process

### Grade 8 SCIENCE Unit 3 FLUIDS Chapter 7 QUESTIONS

Grade 8 SCIENCE Unit 3 FLUIDS Chapter 7 QUESTIONS Page 272 1. A FLUID is a substance that can be made to FLOW. If a material, FLOWS, it is a FLUID. If you can STIR it, it is behaving like a FLUID. 2. Particle

### MAKING SOLID SOLUTIONS WITH ALKALI HALIDES (AND BREAKING THEM)

MAKING SOLID SOLUTIONS WITH ALKALI HALIDES (AND BREAKING THEM) John B. Brady Department of Geology Smith College Northampton, MA 01063 jbrady@science.smith.edu INTRODUCTION When two cations have the same

### Method 108C - Determination of Arsenic Content in Ore Samples From Nonferrous Smelters (Molybdenum Blue Photometric Procedure)

While we have taken steps to ensure the accuracy of this Internet version of the document, it is not the official version. Please refer to the official version in the FR publication, which appears on the

### Pre-Lab Exercises Lab 8: Biochemistry

Pre-Lab Exercises Lab 8: Biochemistry Name Date Section 1. List the 3 basic components of a DNA nucleotide, and draw a simple picture to show how they interact. 2. Consider the amine bases in DNA. List

### USEPA Membrane Filtration Method Method m-tec. Scope and Application: For potable water, nonpotable water, recreation water and wastewater.

, MF, m-tec, 8367 DOC316.53.001210 USEPA Membrane Filtration Method Method 8367 1 m-tec Scope and Application: For potable water, nonpotable water, recreation water and wastewater. 1 USEPA accepted. Test

### Algae Balls. Investigating Photosynthesis. Student Materials. Introduction Lab Protocol Data Collection Worksheet... 5

Algae Balls Investigating Photosynthesis Student Materials Introduction... 2 Lab Protocol... 4 Data Collection Worksheet... 5 Pre-Lab Questions... 8 Post-Lab Questions and Analysis... 9 Last updated: October

### Delaware Science Assessment Prototype: Grade 8 Integrative Item Cluster

Student Version Delaware Science Assessment Prototype: Grade 8 Integrative Item Cluster Prepared for the Delaware Department of Education by WestEd Hot Pack Investigation #1 A student investigated how

### Brian Cox school experiments How can we clean our dirty water?

Brian Cox school experiments How can we clean our dirty water? Water covers most of the Earth and is vital for creating and sustaining life. Of all the world s water, approximately 97% is found as salt

### Product Information CHEMGLAZE B 9942 A/B. Coating for Casting Pits. Easy Application Chemglaze B 9942 A/B will bond to damp and wet surfaces.

Product Information Chemical Products Division CHEMGLAZE B 9942 A/B Coating for Casting Pits. FEATURES BENEFITS. Easy Application Chemglaze B 9942 A/B will bond to damp and wet surfaces. Will build to

### EMG 807 Post-test. 1. Workers from the electric company regularly read the meters on houses. These meters measure the amount of

EMG 807 Post-test 1. Workers from the electric company regularly read the meters on houses. These meters measure the amount of a. Energy that we use. b. Power that we use. c. Force that we use. a. i only

### ERT 318/4 UNIT OPERATIONS SEMESTER 1 (2013/2014)

ERT 318/4 UNIT OPERATIONS SEMESTER 1 (2013/2014) WATER COOLING TOWER School of Bioprocess Engineering University Malaysia Perlis EXPERIMENT Water Cooling Tower 1.0 OBJECTIVES 1.1 To determine energy and

### By Authority Of THE UNITED STATES OF AMERICA Legally Binding Document

By Authority Of THE UNITED STATES OF AMERICA Legally Binding Document By the Authority Vested By Part 5 of the United States Code 552(a) and Part 1 of the Code of Regulations 51 the attached document has

Procedure for the Assaying of TECHNICAL GRADE MOLYBDENUM OXIDE GUIDELINES FROM R INTRODUCTION This Guideline on good practice in relation to the Assaying of Molybdenite Concentrates is one of a six part

### Stoichiometry. Lab. FCJJ 16 - Solar Hydrogen Science Kit. Next Generation Science Standards. Initial Prep Time. Lesson Time. Assembly Requirements

Next Generation Science Standards NGSS Science and Engineering Practices: Asking questions and defining problems Developing and using models Planning and carrying out investigations Analyzing and interpreting

### YEAR 7 SCIENCE EXAMINATION. Semester MULTIPLE CHOICE QUESTION BOOK 1 MATERIAL REQUIRED / RECOMMENDED FOR THIS PAPER:

YEAR 7 SCIENCE EXAMINATION Semester 2 2016 MULTIPLE CHOICE QUESTION BOOK 1 STUDENT NAME: TEACHER: DATE: Time allowed for this exam: (Book 1 and Book 2 Combined) Reading time before commencing work: Working

### Nickel Electroplating

Nickel Electroplating In a galvanic or voltaic electrochemical cell, the spontaneous reaction occurs and electrons flow from the anode (oxidation) to the cathode (reduction). In an electrolytic cell, a

### SAFETY DATA SHEET according to 1907/2006/EC, Article 31

SAFETY DATA SHEET according to 1907/2006/EC, Article 31 SECTION 1: Identification of the substance/mixture and of the company/undertaking 1.1. Product identifier Product name 1.3. Details of the supplier

### Experiment 3: The Chromatography of Organic Compounds

Experiment 3: The Chromatography of Organic Compounds INTRODUCTION Very often, in an organic synthesis, a reaction will proceed to produce multiple products or perhaps will only partially form the desired

### Analysis of Calcium Carbonate Tablets

Experiment 9 Analysis of Calcium Carbonate Tablets Prepared by Ross S. Nord, Eastern Michigan University PURPOSE To perform a gravimetric exercise to determine weight percent of active ingredient in a

### EXTRACTION EQUIPMENT:- 1. Single stage mixer settler 2. Multi stage mixer settler 3. Spay tower 4. Packed tower 5. Tray tower

EXTRACTION EQUIPMENT:- 1. Single stage mixer settler 2. Multi stage mixer settler 3. Spay tower 4. Packed tower 5. Tray tower DEFINATION:- EXTRACTION Extraction is the method of separating the liquid mixture

### Teknik Bioseparasi. Dina Wahyu. Genap/ Maret 2014

4. Teknik Bioseparasi Dina Wahyu Genap/ Maret 2014 Outline Chemical Reaction Engineering 1 2 3 4 5 6 7 Pendahuluan mempelajari ruang lingkup teknik bioseparasi dan teknik cel disruption Teknik Pemisahan

### Acid Rain. Evaluation copy. Figure 1: Typical rain ph in United States.

Acid Rain Experiment 2 Acid rain is a topic of great concern to environmental engineers. It can kill fish by lowering the ph of lakes and rivers. It can harm trees and plants by burning their leaves and

### Etching Aluminium and Zinc with Copper Sulphate

Introduction Etching Aluminium and Zinc with Copper Sulphate Etching aluminium or zinc in a solution of copper sulphate is not a new idea. In recent years the movement in printmaking to improve traditional

### MOLYBDENITE CONCENTRATES

Procedure for the Assaying of MOLYBDENITE CONCENTRATES GUIDELINES FROM R INTRODUCTION This Guideline on good practice in relation to the Assaying of Molybdenite Concentrates is one of a six part series

### Antigen-Antibody Interaction: The Ouchterlony Procedure. Storage: Some components require refrigerator storage. See page 3 for storage requirements.

The iotechnology Education Company 270 EDVO-Kit # Antigen-Antibody Interaction: The Ouchterlony Procedure Storage: Some components require refrigerator storage. See page 3 for storage requirements. EXPERIMENT

### Pre-Lab 5: Magnesium and Magnesium Oxide

Name: Pre-Lab 5: Magnesium and Magnesium Oxide Section: Answer the following questions after reading the background information at the beginning of the lab. This should be completed before coming to lab.