Physical vs. Chemical PROPERTIES of Matter Web view2. rusting steel. 3. photosynthesis. ... Painting...

Science 7 Mrs. Clement

Unit 3 Chemistry: Physical & Chemical Changes

What You Will Learn:

What is physical change? What is chemical change? How concentrated

solutions and diluted solutions are different

How to identify acids and bases

How to separate the parts of a solution

What are acids and bases? How can you separate

solutions?

Why is this important?

Have you ever wondered how weak tea is different than strong tea?

Water dissolves a wide variety of substances. Some substances are healthy, some not affect you, and some are harmful. Knowing about solutions helps you understand the meaning of “safe drinking water”

You use acids and bases to clean your home, your clothes and yourself. Acids and bases affect the taste of your food and the well being of the environment.

How can you make your own makeup? Your own deodorant?

Just how acidic IS your shampoo anyway?

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A Glance into the Future

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Pre-quiz check in Lesson Key Words

Textbook pages

Post-unit check in

3.1 Chemical and Physical Changes

Chemical in Matter Physical Change Chemical Change

Physical changeModelParticle model of matterChemical changeChemical property

122

3.1 Solutes and Solvents What is Insoluble Particle Model of Matter Dilute or Concentrate

SolubleInsolubleConcentrated dilute

160

3.2 Dissolving A limit to dissolving LAB #1 Solubility Rate of dissolving Temperature and rate of

dissolving Size and rate of dissolving

SaturatedUnsaturatedSolubilityRate of dissolving

165

3.3 Acids and Bases intro identifying acids and

bases LAB: shampoo Acids and Bases in action

IndicatorAcidBasePH scaleNeutral

175

3.4 Processing Solutions Separation by

Crystallization LAB: salt from salt water Separation by distillation Purifying water

CrystallizationDistillation

180

Unit Review & Quiz

Recap Key words


3.1 Chemical and Physical Changes

(Textbook 122)

So many kinds of Matter: Elements, Compounds, and Mixtures!

Elements have been defined as ______________ made up of only one kind of ____________. Each element may be made up of many atoms, but each atom in the element is exactly the same. Each element’s atoms are different from atoms of every other element.

Sometimes elements combine. When they combine by means of a _________________________, the properties of the individual atoms change. The combined atoms form a ___________________. The molecule has new properties that are different from the properties of individual atoms.

Compounds have defined as two or more kinds of __________________ that have combined in a chemical reaction.

There are times, however, when matter combines without a chemical reaction and a ____________ is formed.

A mixture can be defined as two or more ________________ or ___________________, or both, that have combined without a chemical reaction. Because there is no chemical reaction, the properties of the elements and compounds do not change when they form a mixture.

What are some examples of…Compounds:

Mixtures:

Now, let’s suppose that it’s early spring and you are planting a small vegetable garden. What is the soil made of? What are you planting? Are there rocks or sand particles in the soil?

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OOPS! While you are working, you accidentally cut your finger on something sharp. What do you notice? You begin to bleed. Is your blood a mixture? Let’s see if it fits our definition:

Is it made up of two or more elements or compounds? ____________. It contains red and white blood cells, water, and a number of dissolved elements.

Are the different kinds of matter combined in a chemical reaction? _____________. Your body needs to use the many parts of your blood. They are mixed together, but can be separated.

So, the blood is a mixture because it is made up of two or more elements or compounds that are not combined in a chemical reaction.

Look around you. You can probably find many examples of mixtures. Most of the matter around you is in the form of mixtures. The _________________________ are solid, liquid, gas and plasma. Matter can undergo different kinds of changesphysical, chemical and nuclear. A _________________ in matter is one in which the form or _____________________ of matter changes but not its _____________ makeup. Whenever you cut, tear, grind or bend matter, you are causing physical change. The size and shape of matter has been changed without changing the physical makeup. Tearing paper changes its physical appearance (shape and size), but does not change its chemical makeup. It is still paper.

Physical ChangesPhysical changes includes changes in the ___________ or ____________ of matter. Heating and cooling can change matter from one state to another. Ice changing into water is a _______________________ where ice (a _________________) is changed to water (a _______________).

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During a physical change in matter, ___________ stays the same because there is not a gain or loss of matter. This is referred to as the _________ _____________________________.

The molecules in matter are always __________________. Their speed changes when they are _____________ or ______________. If a substance is heated or cooled enough, it changes state or form. The molecule is a solid move back and forth, but they do not move away from each other.

The change from a solid to a liquid is called: __________________. The temperature at which a substance changes from a solid to a liquid: ________________________.

When a liquid cools, its molecules slow down and may even freeze. The change from a liquid to a solid state is called _______________. The temperature at which a substance changes from a liquid to a solid is the ____________________.

___________________ is the process of a liquid changing from a gas when it is heated. When

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mouthwash is passes through your body, it has a cooling sensation because the heat in your body quickly changes the mouthwash to a gas.

___________________ is the process of a gas changing to a liquid when it cools. Warm breath on the window causes water vapor to form.

_____________________ occurs when a solid changes directly to a gas without changing to a liquid first. Mothballs change to a gas through sublimation.

_________________________ is the transfer of energy through matter from molecule to molecule. For example, a spoon in a cup of hot soup becomes warmer because the heat from the soup is conducted onto the spoon.

When energy is transferred, the process of __________________ is taking place. The motion of molecules moving causes currents. For example, macaroni boiling in a pot of water.

______________________ is the transfer of energy is transferred by molecules in electromagnetic waves. Radios, microwaves,

Chemical Changes

A chemical change takes place when ____________________ change their chemical structure, producing a ________ substance. The new substance has properties ________________ from the original substances.

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During a chemical reaction, atoms are rearranged into new substances. An animal digesting food is an example of a chemical change.

Chemical change happens at the _______________. A compound is ________________________ substances that are chemically combined to form a new substance. The elements in a compound are held together by chemical _______________. Chemical bonds are formed between the atoms of the elements. There are two main types of chemical bonds:

Ionic bonds: formed when atoms _____________ electrons. Salt is an example of an ionic bond. A sodium atom transfers an electron to a chlorine atom.

Covalent bonds: formed when atoms ________ electrons. Water is an example of a covalent bond. The hydrogen atoms share electrons with the oxygen atom.

Chemical reactions are described using __________________________: a shorthand way of describing the chemical reaction between two or more substance. 2H 2 + 02 2H 20 is the chemical reaction for water. The “+” sign means combine, and an arrow means “yield.”

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The statement above means: 4 hydrogen atoms combine with two atoms of oxygen to yield two water molecules.

During a chemical reaction, matter is not ___________________ or _______________________. All the atoms present at the start of the

reaction are also present at the end of the reaction. This is known as the Law of the Conservation of Mass.

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Evidence of Chemical Change:

How can matter change physically?

How do you think it can change chemically?

In a chemical change, a ________________ takes place. When a scientist combines hydrogen and oxygen to make water, a chemical reaction takes place. Hydrogen and oxygen are two ______________ that have their own properties. They combine, or react, to form a new substance.

Chemical reactions involve two main kinds of changes that can be observed- the information of new substances and changes in energy.

Evidence of Chemical reactions:

1. The formation of gas2. An odour is given off3. A change of colour4. The production of heat or

light5. The formation of a solid

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New Substances Formed:

Oxidation: is the combining of oxygen with other substances. Fire or burning is a chemical reaction. It is the process is called rapid oxidation. When plant matter, such as grass clippings, decays, the plant material is slowly combining with oxygen. This is a process called slow oxidation. Rust is also an example of slow oxidation. Heat is given off in all types of oxidation.

Precipitation: the formation of a solid in a solution during a chemical reaction. When the reaction occurs, the precipitate settles out as a solid in the bottom of the container of liquid.

Changes in Energy:

Endothermic reaction: energy is absorbed. Frying an egg is an example of an endothermic reaction. You must keep adding heat, or the reaction will stop.

Exothermic reaction: energy is given off in the form of heat. Burning wood is an exothermic reaction because heat is given off.

Chemical Property Example Change that occurs

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Due Date: _______________Chemical and Physical Changes

Fill in the Blanks

1. When hydrogen and oxygen combine, ________________ is formed.

2. Rust is an example of slow ____________________.3. ____________________ is given off in all types of oxidation.4. Frying an egg is an example of an _________________ reaction.5. Burning wood is an _____________ reaction because heat is given

off.

Matching1. ________ chemical change a. new energy absorbed2. ________ oxidation b. a new substance is formed3. ________ precipitation c. energy is given off

Example Type of Reactions Released/Absorbed

1. Rotting wood

2. rusting steel

3. photosynthesis

4. cooking an egg

5. heating with coal

4. ________ endothermic reaction d. combing of oxygen with other substances

5. ________ exothermic reaction e. formation of a solid in a solution6. ________ chemical change f. atoms share electrons7. ________ ionic bond g. a new substance is formed8. ________ covalent bond h. atoms transfer electrons

Endothermic and Exothermic Reactions. Complete the table as endothermic or exothermic reaction. Is energy released or absorbedPhysical and Chemical ChangesComplete the following data table with either physical or chemical change.

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Change Type of ChangeFreezing waterRotting woodCake bakingBurning paperBread moldingIron rustingCrushing rockDrying cloth

Chemical FormulasComplete the table by classifying each example as a chemical equation or chemical formula.

Example Chemical equation OR formula?C 022H 2+ 02 2H 20FE + S FeS

NaCl

CompoundsWrite the formula for each compound.

Example Chemical equation OR formula?Sodium hydroxideCarbon dioxideSodium chlorideCalcium carbonatePotassium nitrate

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3.2 Solutes and Solvents(textbook p.165)

Soluble: ______________________________________________Insoluble: ____________________________________________

To keep cut flowers fresh longer, some people like to add a little sugar to the water vase. Why do you think this is?

LAB Results

Bowl

Solvent Solute Observations

1

2

3

4

LAB #1: Does it dissolve?

In this activity you will investigate whether salt and flour are soluble or insoluble in two different solvents.

Materials:4 sm glass bowls4 labels4 stir stickswaterveg. oilsaltflourmeasuring spoons

Procedure:1. Use the table below to copy down your answers.2. Label the bowls 1, 2, 3, 4.3. Measure 2mL of water into cups 1 and 2. Measure 2mL of oil into

bowls 3 and 4.4. Record the solvents (oil or water) onto the table. 5. Predict whether each of the solutes (flour and salt) will dissolve

in one, both or neither. Record your predictions. 6. Stir in a tsp. of salt into bowl 1 and 3. Record the name of the

solutes and your observations. 7. Stir the flour into bowls 2 and 4. Record your observations.8. Clean up the materials. Complete the table and questions.

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What did you find out?1. Summarize your results using complete sentences.

________________________________________________________________________________________________________________________________________________________________________________________________________________

2. Were your predictions correct?________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Solutes may be soluble, insoluble or partly soluble. What observations might indicate that a solute is partly soluble?________________________________________________________________________________________________________________________________________________________________________________________________________________

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Soluble Substances and the Partible Model of Matter

How can we model what happens when a soluble substance dissolves in a solvent?

Dilute or Concentrated?

4TH RULE:ALL PARTICLES ARE ALWAYS IN MOTION, THEY VIBRATE, ROTATE,

AND (IN LIQUIDS AND GASES) MOVE FROM PLACE TO PLACE.

LAB #2: Molecular Workbench

In this activity you will investigate modeling particles in motion using a computer simulation activity.

Materials:Computerwww.mw.concord.org/modeler/download.html

Procedure:1. Log on to the website above2. Choose Phase Change OR heat and temperature.3. Follow the instructions on each slide. Take a picture of the

simulations.4. Print your final results with completed answers.

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http://www.mw.concord.org/modeler/download.html


You and your friends are making hot chocolate. Your friend mixes four spoonful’s of hot chocolate powder into a mug of hot water. You mix two teaspoons of hot chocolate powder into another mug of hot water. Whose hot chocolate is more concentrated, your or your friends?

Concentrated solution: _______________________________________

Diluted solution: ____________________________________________

Concentration

The _________________ that is dissolved in a certain quantity is the concentration. You can describe this concentration as “concentrated” or “dilute.”

You can change the concentration of a solution by: adding more ____________ to make the solution more

concentrated. adding more ____________ to make the solution more dilute.

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3.3 Dissolving(textbook p.165)

If you put a teaspoon of salt into a glass of water, the salt will dissolve. Suppose that you put a second spoonful of salt into the water; then a third and a fourth. The solution is becoming more and more concentrated. Will each spoonful dissolve like the spoonful before it? Draw a diagram to help you.

A Limit to Dissolving:

Saturated Solution:- Forms when _____________ solute

will dissolve in a specific amount of solvent, even with plenty of stirring.

o Salt, for example, is formed when 35.7g of salt is dissolved in 100g of water at 0°.

o If more salt is added, it will not dissolve.

Unsaturated Solution:- forms when more solute ___________

dissolve into a solution.o Sugar, for example, in a cup of

tea, dissolves.

Solubility

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Solubility refers to the ____________ of solute that can dissolve in a certain volume or mass of solvent, at certain temperatures.

Substance State Solubility (g/100g water)Baking soda 6.9Canola oil InsolubleCarbon dioxide 0.34Epson salts 70.0Ethyl alcohol UnlimitedLimestone 0.0007Nitrogen 0.003Oxygen 0.007Salt 35.7Sugar 179.2

Compare the masses of different solutes that dissolves in water at 0°C. The most soluble (solid) substance is sugar. Amazingly, you can dissolve nearly 180 g of sugar in only 100g of water!

Rate of DissolvingAs you have discovered, the mass of a

solute that will dissolve in a solvent depends on temperature. What factors do you think might affect how fast a particular mass of solute will dissolve?

When you measure how fast a solute dissolves, you are measuring the __________________________. For example, when you add fruit crystals to a jug of water, you have probably notices that the crystals dissolve slowly. This is because the solution that is close to the crystals is concentrated, while the solution further away is more dilute. When you stir mixture, you push some of the more concentrated solution away from the crystal.

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LAB #3: More Tea Please!

Question: Does heat affect dissolving rates? Can you dissolve more sugar in cold tea or hot tea?

Hypothesis: _______________________________________________ ________________________________________________________

Purpose: In a solution, there is usually a liquid (SOLVENT) and a solid (SOLUTE) that gets dissolved in the liquid. In this activity, we actually experiment to find out how the temperature of a liquid effects how much solid can be dissolved in it. We will also weigh the solid dissolved.

Materials:3x 250mL beakerglass stirring stickssugarkettle300 mL tap waterice cubesscale (to weigh results)thermometer

Procedure:1. Label three beakers COLD, ROOM, HOT2. Set up each beaker with the following:

a. COLD: Add 100mL of water and ice cubesb. ROOM: Add 100mL of tap waterc. HOT: Add 100ML of boiling water

3. Weight your beaker. Record the original weight of each SOLVENT4. Weigh out about 50g of sugar. Begin at the room temperature beaker,

adding the sugar, stirring and observing results. Weigh the beaker with the newly added SOLUTE.

5. Graph the results of the temperature of the water with the solvent, and the weight of the beaker after the addition of solvent.

6. Repeat for ROOM and HOT

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LAB results

Temperature vs. Solubility

Conclusion: _________________________________________________________________________________________________________________

1. How many grams of sugar would dissolve halfway between room temperature and cold?

2. In which temperature can tea dissolve the most sugar?

Amount dissolved (grams)

Temperature (Celsius)

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Due Date: _______________Review of chapter 3.3

1. Temperature and Rate of DissolvingDoes the particle model also explain the effects of temperature on the rate of dissolving?

2. Size of Solute and Rate of Dissolving: Why do smaller pieces of solute dissolve faster than larger pieces?

BONUS LAB (conduct the following lab at home. Record your results in the table below.)

Substance Powder or crystal

Prediction: what will happen when mixed with water?

Observation: what actually happened?

High solubility or low solubility?

flour

sugar

Baking soda

salt

cornstarch

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3.4 Acids and Bases(textbook p.175)

To measure the PH (level of acidity and basicity) of each solution, you can use __________________.

1. Tear off a piece of litmus paper.2. Dip one end into a solution and remove it immediately.3. Compare its new colour with the colour chart provided below.4. Record the PH number that matches the colour chart in the

chart on the next page, and determine whether the PH number represents acid, base, or neutral.

5. Discard that litmus paper, and repeat for each new solution.

Test solution Colour Acid, base, neutral

PH number

You

Vinegar

Baking soda

Tap water

Saliva

Soft drink

Lemon juice

Ammonia

Conclusions: _______________________________________________ __________________________________________________________________________________________________________________Acids and Bases

Chemical compounds that taste sour, react with metal to produce hydrogen gas, and conduct electricity are called ___________.

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Some foods, such as lemon juice, contain acids. However, many acids are too strong to taste or even touch. One of the strongest acids is ___________________. Sulfuric acid is used in car batteries because it is a good conductor of electricity. Most acids are made of one or more hydrogen atoms. In the chemical formula for most acids, ________________ is the first element. The chemical formula for hydrochloric acids is ____________.

Chemical compounds that taste bitter, feel slippery, dissolve oils and fats, and conduct electricity are called ____________. Ammonia, lye, and bleach are bases. Like acids, strong bases can also be dangerous to taste or touch. Most bases are made of _______________ and _____________ atoms linked together. These are called ___________________. The formula for hydroxide is OH. It is always written last in a chemical formula. The chemical name for lye is sodium hydroxide. The formula. SOH.

Sometimes the substances we are testing is neither an acid nor base. It is __________________. When an acid and base react chemically, they neutralize one another. The hydrogen from the acid combines with the base’s hydroxide to form water. Water is a _______________________. Salt is another neutral compound produced when acids and bases react chemically.

Litmus paper: ______________________________________________PH scale: _________________________________________________

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Due Date: _______________Acids and Bases

1. What are the three properties of acids?

2. What is one substance that you could use as an indicator?

a. Suppose that you used the indicator you named above to test an unknown solution. What colour changes would occur if the solution were an acid?

b. What colour change would occur if the solution were a base?

3. An unknown substance was tested with litmus paper. Red litmus turned blue and blue stayed blue. Is the substance an acid or base?

4. Use the litmus paper provided by your teacher to test four products at home. Record your results in the table below. Find two items of your own choosing.

Item Colour of paper

PH level Acid, base, neutral?

ShampooConditionerDish soapLaundry soapTap waterOther:Other:

Read the article below. Can you make your own cosmetics?

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How to Get Balanced SkinBy April Long (Feb 23, 2011)

"Skin with a balanced pH appears healthier, is slightly moist, looks plumper, and has a healthy glow," Sobel says, whereas skin that's too alkaline "may be acne-prone, dry, or excessively oily." In other words, if you have a persistent skin problem, from zits to dermatitis, an upset pH could be to blame.

The chief culprit in raising alkalinity sounds perfectly innocent: washing skin with soap and water. "Soaps are very alkaline," Sobel says, "so using them can increase skin alkalinity above its natural levels." Traditional bars can have a pH of up to 9, leaving an alkaline residue on the skin that renders it dry and vulnerable to damage. That tight feeling you get after washing your face with hotel-issue hand soap, for example? Not a good thing.

Thankfully, excessive alkalinity can be easily addressed. First of all, drop the soap and switch to a cleanser (foaming is generally considered best for acne-prone skin, non-foaming or milky for dry skin) that won't strip away the skin's natural oils. There are also, Sobel says, "several effective treatments that can help the skin be more acidic, such as glycolic peels, which have an exfoliating effect." Manhattan dermatologist Dennis Gross, MD, says peels can help regulate pH but can be too acidic; to that end, his own home peel line includes a second neutralizing step.

An overly acidic epidermal pH, while less common than skin that has become too alkaline, can result from too strong (or too frequent) peels, manifesting itself in a sensitive, irritation-prone complexion. The good news? When you're using the right products, the skin's barrier will always return to its natural, pH-balanced happy place.

Like Young, Graf approves of the use of vegetable-based juice cleanses to kick-start the change over to a more alkaline diet: Indeed, while such cleanses are popular for detoxification and weight loss, they're also restoring alkalinity to the cells. "Even if you have only one day when you're doing nothing but drinking green juice and lots of water, your pH will go up," she says. "If you take mineral supplements and eat salads every day, your pH will go up." Graf recommends using the aforementioned saliva pH–testing strips periodically to check that your levels don't stray from between 7 and 7.5—but there's no need to obsess. "Your barometer should just be feeling good and looking good. When you've hit the right pH balance, you'll know."

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Chemistry you can FEEL good about…You have decided to open up your own organic cosmetic shop

“Formula CH2CH3CH4beauty.” You have researched some recipes online, but are unsure of their PH levels. In order to ensure that you are selling a product that will not burn or dry out your clients skin, you must test the recipes and their PH levels. Create one of the following recipes. Test the PH with a litmus test and record your results. Are you willing to test your product for yourself?

A Soothing Hand Scrub

Ingredients:

1 tablespoon sugar1/2 tablespoon salt (regular salt that you use on food)5 small squirts honey

1/4 tablespoon corn starch or flower1/2 cup milk1/2 cup water

Blending Procedure: 1. In one bowl add the liquid ingredients together (milk, water and

honey)and set aside2. In a larger separate bowl, mix together the dry ingredients (corn starch

or flour, sugar and salt)until fully distributed. 3. Gradually pour liquid ingredients into the bowl of dry ingredients

mixing constantly. 4. Once bowl is full, place hand in bowl and gingerly rub mixture over

hands.5. Let hands soak for 5 minutes or so then rinse and pat dry hands.6. Discard after use.

Chocolate Facial Mask This decadent mask is actually an excellent moisturizer - it leaves your skin baby soft. Recommended for normal skin.

Ingredients:

1/3 cup cocoa 3 tablespoons heavy cream 2 teaspoons cottage cheese

¼ cup honey 3 teaspoons oatmeal powder

Instructions: Mix all ingredients together and smooth onto face. Relax for 10 minutes, then wash off with warm water

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Avocado Carrot Cream Mask This mask is rich in vitamin E, beta carotene, antioxidants, calcium and protein, ingredients that may help rebuild skin collagen, fade age spots and improve tone and texture.

Ingredients: 1 avocado, mashed 1 carrot, cooked and mashed 1/2 cup heavy cream

1 egg, beaten 3 tablespoons honey

Instructions: Combine all ingredients in a bowl until smooth. Spread gently over your face and neck, and leave in place 10-15 minutes. Rinse with cool water and follow with your favorite toner.

Herbal Acne TreatmentInstructions:1. Steam your face for five to 10 minutes to clean the pores with hot infusions of lavender, chamomile or thyme.2. Rinse your face with honeywater, rosewater or a dilute infusion of marigold tea to tone and close the pores.3. Do this every day until the skin starts to heal

Baking Soda Mask to Fight AcneThis is so easy to make and can work wonders if your skin likes it.

Ingredients:1 tablespoon baking soda (NOT baking powder)1-2 tablespoon water

Instructions:Mix a little together in your hands after washing your face with a mild cleanser and apply gently to your skin. Once you've coated your face with the baking soda and water mix, let it sit while you do other things around the house, or relax and read a book. Rinse the baking soda film off your face and feel how soft and clear it feels. If your skin enjoys this recipe, and your acne improves, then you may try it several times a week to help clear your acne.

3.5 Processing Solutions(textbook p.180)

Boiling a solution is a common method for separating a solute from a solvent. As the liquid evaporates, the solute remains. Therefore, the

Tech Connect: http://www.iun.edu/~cpanhd/C101webnotes/chemical%20reactions/ioniccmpdsol.html

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http://www.iun.edu/~cpanhd/C101webnotes/chemical%20reactions/ioniccmpdsol.html


solution becomes more and more concentrated. You have probably eaten a solution processed by boiling- maple syrup.

Separation by CrystallizationWhen water evaporates from saltwater lakes during dry, hot, summer months, the salt is left behind. This process is called __________________.

Separation by DistillationDistillation lets you recover both the _____________ and the __________. During distillation, the solution is ________ until the solvent changes to a gas. Then the gas is condensed back into a liquid by cooling. The solute does not change state when it is left behind.

Tech Connect: http://www.iun.edu/~cpanhd/C101webnotes/chemical%20reactions/ioniccmpdsol.html

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http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf

http://www.northland.cc.mn.us/biology/Biology1111/animations/dissolve.html


Purifying WaterWater quality is important to human health. Where does your drinking water come from?

Depending on where you live, water likely comes from the nearest lake, reservoir, or well. NO matter what the source, usually water needs some sort of treatment to be drinkable.

Water is purified for drinking using both physical and chemical methods. For example, flotation and _________________ are used to remove solid matter. After solid matter had been removed, chemicals are added to the water to kill bacteria and balance the PH.

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Due Date: _______________Summary of Ideas

Summarize your understanding with one of the following activities:a. Use a concept map (graphic organizer)b. Create a posterc. Write a summaryd. Draw a cartoone. Radio program/ announcementf. Videog. Board game

The points mentioned on the next page “TO RECAP” must be included in your presentation, whichever format you choose. You CAN work with a partner. If you choose to summarize your understanding with a method different than the one mentioned above, please see me first.

Here are some ideas as your guide. - use drawings or differently coloured marbles to model the

followingo dilute solutiono a concentrated solutiono dissolvingo the effect of stirring on dissolving

- create a PH scale poster. Cut out pictures of foods and household products

- Create a flowchart to show how you would separate o Salt, water, and marbleso Sugar and peppero Epson salts, iron filings and sand

- Make a slap jack game to demonstrate the elements symbols (example, C calcium)

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To Recap:

A substance is soluble in a solvent when it dissolves in solvent. For example, salt it soluble in water

A substance is insoluble in a solvent when it does not dissolve in solvent. For example, diamonds are insoluble in water.

A concentrated solution has a large mass of solute for a certain volume of solvent.

A concentrated solution has a large mass for a certain volume of solvent,

A dilute solution has a small amount of solute for a certain volume of solvent.

When a solution is unsaturated, more solute can dissolve at the same temperature. When a solution is saturated, no more solute will dissolve at the same temperature.

Different solutes have different solubility. The solubility of a solid in a liquid can be increased by increasing the temperature.

The rate at which a solid dissolves in a liquid can be increased by stirring the solution, increasing the temperature of the solution or increasing the area of the solid by breaking it into smaller pieces.

Neutral solutions have a PH of 7 Acids PH less than 7 Base PH more than 7 Crystallization occurs when a solvent evaporates from a

concentrated solution, leaving crystals of solute behind. In distillation, a solution is heated until the solvent

changes to a gas. Then the gas is condensed back into a liquid by cooling.

Water can be purified for drinking using both physical and chemical means.

Physical vs. Chemical PROPERTIES of MatterProperties (physical and chemical) of a substance are those characteristics that are used to identify or describe it.

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So far we have studied the physical properties of matter. Physical properties are observable (qualitative) like size, lustre, smell, colour, or state of matter. Or, Physical properties are measurable (quantitative), such as mass, volume, density, temperature, boiling point, and melting point.

Chemical properties are only observable during a chemical change (also called a chemical reaction).

Physical vs. Chemical CHANGES in MatterPhysical changes are those changes that do not result in the production of a new substance. For example, if you melt a block of ice, you still have H2O at the end of the change. If you break a glass bottle, you still have glass. Painting a piece of wood will not change the wood into something else.

Chemical changes, or chemical reactions , are changes that result in the production of another substance. When you burn wood (in fact, when you burn anything), a chemical reaction occurs that produces

Wow! There are a lot of physical properties! And that’s not all of them.

Chemical properties describe how chemicals behave when they react with one another.

EXAMPLES Many metals (iron, silver,

magnesium) react with oxygen (they “rust”)

Metals usually react with non-metals

Hydrogen reacts with many non-metals to form acids

Many carbon-hydrogen molecules (wood, paper, gas, oil, wax) react with oxygen to produce heat, water and carbon dioxide

mass volume density

(mass/volume) boiling point melting point temperature malleability elasticity hardness viscosity plasticity conductivity strength solubility state of matter lustre colour odour texture shape transparency

(opaque/translucent)

Chemical PropertiesPhysical Properties

Properties of Matter

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new substances. The wood, like other types of fuel (made of carbon, hydrogen and oxygen) chemically changes to form water (vapour) and carbon dioxide. If the burning is not complete, sometimes carbon, in the form of ash, is also produced. CxHxOx + O2 + heat H2O + CO2 (+ Cx)Some everyday examples of chemical change include digestion and decomposition (large complex molecules break down into smaller molecules), photosynthesis H2O + CO2 C6H12O6 (glucose) + O2respiration (burning) C6H12O6 (glucose) + O2 H2O + CO2

Changes in Matter

Physical Changes Chemical Changes Changes of State

melting freezing evaporation condensation sublimation deposition

Changes in Size or Shape crushing breaking bending cutting

Five Indicators That A New Substance Has Been Formed

1. Colour changes 2. A gas is produced3. Temperature changes4. Light or sound is

produced5. Precipitate is formed

(when a solid formed by a reaction in solution)

Yeah! I get it, physical changes don’t result in a new substance, but chemical changes do!

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Physical vs. Chemical PROPERTIES of Matter Web view2. rusting steel. 3. photosynthesis. ... Painting...

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Transcript of Physical vs. Chemical PROPERTIES of Matter Web view2. rusting steel. 3. photosynthesis. ... Painting...