swensonspage.weebly.com€¦ · web view• msds — material safety data sheets provide detailed...

Science 10-4UNIT A- “The Chemistry Unit” CHAPTER 11.1 Chemicals All Around Us

From the time you get up in the morning to the time you go back to bed, you use _________________.

The toothpaste you use to brush your teeth and the clothes you wear contain chemicals. So do the substances that make up your body. Some chemicals used around the house can __________________.

THINK & WRITEList 5 common chemicals that you might come into contact on a daily or weekly basis:1-2-3-4-5-

Chlorine is useful because it is poisonous.

Chlorine is useful because… ___________________________________________

The danger of Chlorine is… ____________________________________________

Other common household materials have similar dangers.

Match the correct words: Methane Ammonia Lye

______________ is in many household cleaners.

______________ is used in soaps and oven cleaners.

______________ is a common fuel.

If not handled properly, each of these chemicals can _______________. Chemicals can also pose hazards when ____________________.

The chemical reactions that occur can form even more dangerous chemicals. Such reactions can produce ____________________, ____________________, or ___________________. Other chemicals are harmful to the environment.

THINK & WRITEThe table 1.1 on Page 6 outlines the uses and dangers of six chemicals you probably have around your home. Come up with at least two types of job titles that use all (or most) of these products.

Chemical Storage and Disposal

Some chemicals are not just dangerous when you are using them. They can also be dangerous if they are not properly _____________ or _________________.

THINK & WRITEWhere should household products that contain toxic chemicals be stored?

Bleach and ammonia can react strongly to one another, so they should be stored separately from each other. Containers of oven cleaner may explode if ______________ or ______________, so they should be stored away from heat.

Gasoline, camping fuel (for example, propane), and paint thinner (for example, Varsol™) catch fire so easily that they should be stored outside your living area. Do you have any of these chemicals inside your living area?

THINK & WRITEWhere are the chemicals that catch fire stored at your house? List two, and where they are kept.

Special care is also needed when disposing of chemical substances. Simply dumping them down the drain or in a landfill can cause ___________________________________. Many products have ________________________ on the label.

Household hazardous products can be taken to a special municipal collection site. Such sites may be located at the local fire station or in a special area of a landfill site. Products such as _________________ and _________________ can be taken to service stations for recycling.

Chemicals at Work and School

You do not have to memorize how to use and dispose of chemicals safely.

You just have to remember to ___________________________.

The Workplace Hazardous Materials Information System (WHMIS) provides detailed information on how to __________, ______________, and ___________ of any chemical found in the workplace — including schools.

It also provides first aid information.

Information is provided in three ways:

• labels — All hazardous materials have a WHMIS label, which summarizes safe handling procedures.

• MSDS — Material Safety Data Sheets provide detailed information about each chemical. The information includes physical and chemical properties, safe handling, first aid, and disposal procedures.

• worker education — As part of their job, workers who use dangerous substances must take WHMIS training. Employers are required to provide the training.

Chemicals at Home

The symbols on the products you use at home are called Hazardous Household Product Symbols (HHPS). These symbols are found on household products that are reactive or dangerous. Like WHMIS symbols, they alert you to _____________________. Read the label carefully to determine exactly what the hazard is.

WORK: Check Your UnderstandingPage 9All QuestionsFull sentences, Complete Answers.

Terms and Definitions:WHMIS

MSDS

HHPS

1.2 Describing Matter

Matter is anything that has ____________ and ________________________. You are surrounded by it. You are also made up of it. All ________________ substances are considered to be matter. An ancient Greek philosopher named Democritus thought all matter was made up of __________________ too small to be seen. He called these tiny bits atoms.

The word comes from the Greek word for _____________________.

Scientists have spent hundreds of years investigating matter. They developed a theory to help them explain its ______________________. A theory is an explanation of something that has been supported by repeated experimental results. The particle theory of matter helps explain what scientists learned about the nature of matter by thinking of atoms as tiny particles and describing their nature and their ______________ in different substances.

The Particle Theory of Matter

The Theory has 5 parts to it. Each uses the word ‘Particles” in its explanation. The 5 parts are:

Particles are ___________________ Particles are ___________________ Particles always have ____________________________ Particles of the SAME SUBSTANCE are ________________________________________ Particles of the SAME SUBSTANCE are ________________________________________

THINK & WRITEDescribe a situation that you have been in where you have observed that Particles of the SAME SUBSTANCE are attracted to each other? (your description should be a paragraph- 3 to 4 sentences)

States of Matter

Matter exists in three basic states: _____________, ________________, ____________.

The particle theory can be used to explain these three states of matter. See Table 1.2.

In solids, particles are packed tightly together and ___________________ very much. This means that a solid will ___________ its shape and not flow.

In liquids, particles are _____________, but can move past each other. This explains why liquids can take the shape of their container and flow _____________.

Particles in a gas are far apart and moving quickly. Particles in a gas will keep ___________________ from each other until stopped by the walls of a container.

Properties of Matter

Scientists use a variety of physical and chemical properties to identify and classify matter.

When you think of a physical property, consider how you would describe a friend. You might refer to the person’s weight, height, and hair or eye colour. If you were to describe your friend’s character, or the way your friend reacts with other people, you would be talking about qualities that are similar to chemical properties.

A chemical property tells how a substance will ___________ with other ____________________. For example, one chemical property is how easily a substance catches _________. Knowing this information allows us to use a substance safely and effectively. The details of a substance’s ___________ and ____________ properties are usually included on the MSDS.

Some physical and chemical properties are listed in Table 1.3.

THINK & WRITEPick an item that is in your fridge at home, now use Table 1.3 on page 12 to describe your fridge items Physical and Chemical property. (list 4 of each- minimum)


Terms and Definitions:Matter:

Theory:

Particle Theory of Matter:

States of Matter:

Solid:

Liquid:

Gas:

Physical Property:

Chemical Property:

1.3 Classifying Matter

You have learned about the particle nature of matter and the properties of matter. You have also used this knowledge to group and make predictions about different substances. Using the _______________________, we can organize substances into two basic categories based on how many types of particles they contain.

Fill in:

Pure Substances and Mixtures

Have you ever read the label on a package of your morning breakfast drink? Many labels claim that the package contains “pure” juice. Then, when you read the _________________, you notice that the package contains water and a list of other ingredients. It is not “_________” at all — it is a mixture.

Scientifically speaking, a pure substance is made of only one type of __________________. All parts of a pure substance are _________________. Examples include _________________, ____________, and __________. But many items that are advertised as “pure” are actually mixtures. For example, gold is so soft that it has to be mixed with other metals to maintain its shape. Gold ___________________ is usually a mixture. So is juice.

A mixture contains more than one type of particle. In some mixtures, you can see the different types of substances because similar particles stay ______________________________. For example, you can see the different substances that make up salsa and concrete. But you would need a microscope to see the different substances that make up milk, toothpaste, maple syrup, and perfume.

THINK & WRITEList at least 5 pure substances and 5 mixtures that you have used or been in contact with before.

pure substances

mixtures

Differences Between Mixtures and Pure Substances

If you were handed two clear, colourless liquids, and told that one was a mixture and the other was a pure substance, could you tell which was which just by looking at them? Not likely. In order to tell the substances apart, you would have to examine more of their properties.

You might be able to tell them apart by ____________, ______________, or ________________.

You might need to examine their chemical properties. Or you might have to investigate their _____________ and ________________ points. Mixtures boil and freeze at different temperatures than the pure substances that make them up.

Road crews use this property of mixtures to keep roads clear of ice. By adding _________ to the snow and ice on the roads, they create a __________________________ that cannot stay frozen at typical winter temperatures.


Terms and Definitions:Pure Substance:

Mixture:

WORK: Chapter ReviewPage 20Questions 1 to 10Full sentences, Complete Answers.

Unit 1- Chapter 1 Review Check list Complete Review Page 20. (Questions 1 to 10)

Verbally Review Questions 11 to 18 in small groups

Check that your Guided notes are completed

Return all required Handouts for assessment

Prepare for a Unit 1 Chapter 1 test within two operational class days.

Ask questions about material that you are not understanding

Review online Prezi notes for good measure

Science 10-4UNIT A- “The Chemistry Unit” CHAPTER 22.1 Putting the Pieces Together

By the mid-1860s, scientists had discovered 64 _______________ and had recorded many of their ___________. How would you go about organizing all of this information? Elements are substances that cannot be broken down into other substances and contain only one kind of ___________.

THINK & WRITEWithout looking up anything in your textbook or online, what do you remember about the Periodic Table? Write down up to 4 things you remember:

In 1869, Dmitri ___________________ wrote all of the information for each element on a separate file card and then put elements with ___________________________ in columns.

He organized the elements within each group from ____________ to ________________. Then he organized the groups so that the lightest elements were on the left side of the table and the heaviest were on the right side.

As he was working, Mendeleev noticed that some elements appeared to be _______________. He predicted that these elements existed but had not yet been discovered. Mendeleev made cards for the missing elements and even predicted their properties.

The Periodic Table Mendeleev’s work provided the basis for the periodic table. This is a chart on which scientists have organized all of the elements. Mendeleev worked with 64 elements. Since then, the number of known elements has swelled to ___________.

As scientists continue to investigate, they continue to find new ones. Interestingly, scientists have discovered many of the elements that Mendeleev ______________. Mendeleev’s work was so careful and logical that the properties of these newly discovered elements matched his predictions almost perfectly.

THINK & WRITEMendeleev’s organization was impressive and very helpful. Please write down a situation in your life where keeping things organized has saved you time or money? How did you organize it?

Modern advances in scientific technique and apparatus have clarified Mendeleev’s data. Even with these additions, the way the periodic table is arranged has ____________________________ from the way Mendeleev first designed it.

The elements in Mendeleev’s chart are made up of atoms. _____________ are the smallest bits of matter. Water is made up of atoms of __________________ and _________________.

For each atom of oxygen, water has two atoms of hydrogen.

Periodic tables do not all look the same, but they do have some things in common.

• They all look like __________.

• Each square of the table includes ________________ about one element.

The amount of information varies depending on who made the table, but each square usually contains an element’s ________________ and ________________. Some tables include information such as the element’s state, its complete name, and details about the atoms that make up the elements.

Patterns and Trends

The elements in the periodic table are arranged in _________________ and _____________ so that elements with similar properties appear together.

The columns are referred to as _______________.

The rows are called _______________.

THINK & WRITEGo to the very back of your book, use the Periodic Table to find these 4 elements:

1. (Group 1, Period 1): 2. (Group 1, Period 4): 3. (Group 4, Period 10): 4. (Group 2, Period 16):

Metals and Non-metals

Take another look at Figure 2.3. Run your finger along the __________________-like line on the right hand side of the periodic table.

This line separates the __________________ elements from the ________________ elements. The metals are on the left of the line; the non-metals are on the right.

Think back to the various physical and chemical properties you studied in Chapter 1. These properties help distinguish metals from non-metals.

• Metals are good __________________ of heat and electricity. They can be bent, stretched into a wire, and polished until shiny. Metals are ___________ at room temperature. The one exception to this is ______________, which is a liquid.

• Non-metals are poor conductors of heat and electricity. They are dull, not shiny, in appearance. Most are ___________ or ____________________ at room temperature. The exception to this is bromine, which is a liquid at room temperature.

• The white squares between the metals and non-metals show __________________. These elements share some of the properties of metals and some of the properties of non-metals. Your body contains metals, non-metals, and metalloids. ____________ helps release energy to your body cells. __________ is a key element in all sugars, carbohydrates, and proteins. ________________ helps to maintain the fluid balance in your tissues.

Complete the chart:


Terms and Definitions:element :

periodic table:

atom:

group:

period:

metal:

non-metal:

metalloids:

2.1 Elements and Compounds Elements and Compounds in Society Elements and compounds are used all around you. The coins in your pocket, the sugar on your cereal, and the fluid in your car battery are examples of how you use elements and compounds. Everything around us, including our own bodies, can be broken down into the elements that are found in the periodic table.

Compounds

The periodic table lists elements. A substance made up of two or more different elements chemically combined together is known as a compound.

• Oxygen is a pure substance that consists of a single element.

• Distilled water is a pure substance that consists of more than one element.

Distilled water consists of the elements oxygen and hydrogen joined chemically. Water is a compound. Most substances in the world are compounds. You can use this knowledge to add a third level of organization to the flowchart of matter from Chapter 1.

Testing for Compounds

An element is a pure substance that cannot be broken down into simpler substances. Compounds, however, are made up of two or more elements. Compounds can be broken apart into simpler substances. This is done through a process called a decomposition reaction.


Terms and Definitions:Compound:

Decomposition reaction:

2.3 Chemical Names and Formulas As scientists from different parts of the world discovered new _____________________, they quickly realized

that they had a problem. They could not understand each other’s _________________ and names for elements.

In 1919, a group of chemistry organizations from around the world came together to form the International

Union of Pure and Applied Chemistry (IUPAC).

The chemists in IUPAC established an international standard for chemical ________________ and

____________. The standard was based on the names and symbols suggested by a Swedish chemist back in

1817. Today, even students in Japan and Greece learn these ___________________________________ rather

than ones based on their own alphabet.

Element symbols are either one or two letters. Often the first letter of the element name is used. Example: C for

_________________ or N for __________________.

Once scientists ran out of letters, they began using the first letter of the element name and a second letter from

the name. Example: Ca for __________________ and Zn for ___________________.

Some of the elements were discovered in ancient times and have _____________ or _____________ names.

These elements were given a symbol based on their historic name. Example: Pb for lead, which was known in

Latin as plumbum.

Chemical Formulas

We use short forms and symbols to simplify communication. You have already come across some of the short

forms used to represent the elements. In chemistry, we use a different element symbol to represent each

element and a chemical formula to represent the __________________________ these elements form.

Chemical formulas are made up of letters and numbers.

• _________________ tell you which elements are in a substance.

• ______________________ numbers tell you the proportion of these elements in a substance.

• A subscript letter tells you the __________________________.

For example, in Figure 2.13, the chemical formula for water tells you that this substance is made up of the

elements __________________ and _____________________. It also tells you that there are two hydrogen

atoms for every oxygen atom in the substance. In addition, the subscript letter that follows tells you if the

substance is a solid, liquid, or gas at room temperature.


Terms and Definitions:element symbol :

chemical formula:

WORK: Chapter ReviewPage 38Questions 1 -4, 6-8Full sentences, Complete Answers.

Unit 1- Chapter 2 Review Check listComplete Review Page 38. (Questions 1 -4, 6-8)

Verbally Review “Key Terms” p.38 in small groups

Check that your Guided notes are completed

Return all required Handouts for assessment

Prepare for a Unit 1 Chapter 2 test within two operational class days.

Ask questions about material that you are not understanding

Review online Prezi notes for good measure

Science 10-4UNIT A- “The Chemistry Unit” CHAPTER 3

3.1 - Two Kinds of MixturesIn Chapter 1, you began organizing all matter into a flowchart. The first branch represented the

difference between _______________________ and ________________. You learned that pure

substances (such as water or sugar) have only one type of ________________.

Mixtures (such as sugar water) are made up of _________________________ type of particle.

In Chapter 2, you examined the left-hand branch of the flowchart. You learned that pure substances

can be either __________________ or ______________________. In this chapter, you will take a

closer look at mixtures. Figure 3.1 shows that mixtures can be classified into two broad categories:

mechanical __________________ and ___________________. Figure 3.2 shows the main difference

between these two categories.

Mechanical Mixtures

If there ________________ to be more than one type of particle, then you know for sure that you are

looking at a mechanical mixture. You can _________________________________ substances in

mechanical mixtures. Orange juice with pulp is one example. Wet concrete is a mechanical mixture

made from cement, water, sand, and gravel.

THINK & WRITECan you think of other mechanical mixtures around your home? Your kitchen likely has quite a few.Come up with 5:

SolutionsApple juice, iced tea, and window cleaner are all solutions. A ____________________ is made when

two or more substances combine to form a mixture that is uniform or looks the __________________.

In other words, a solution appears to contain only one kind of particle. Shampoo, soda pop,

dishwashing detergent, syrup, and vinegar are other examples of solutions. Before modern detergents,

people added soap flakes to dish-water and waited for the flakes to dissolve. This solution of soap

flakes and water was used to wash dishes.

Today, most people buy solutions ready-made because they are more convenient. It is much easier to

use liquid dishwashing detergent than soap flakes.

Parts of Solutions

Solutions consist of a solute and a solvent.

•The ___________________ is the substance that dissolves.

•The ______________________ is the substance in which the solute dissolves.

There is usually less solute than solvent in a solution.

THINK & WRITE Identify the Solute and the Solvent of the following Mixtures:

a- Kool-Aid

b- Salsa

c- Ice Tea

d- Coffee

e- Smoothies

In salt water, salt is the solute and water is the solvent. If you read the labels on many of the food

products you have around the house, you will notice that water is the solvent for many different

solutes.

How can you tell if a mixture is a solution or a mechanical mixture?

•In a _________________, you should only be able to see one substance.

•A second test is to pour the solution through a filter. If anything is caught in the filter, then the

mixture is _______________________.


3.2 - What Are Solubility and Concentration?Concentration describes the _________________________ in a solution. Manufacturers include the

concentration of the solution on the label of many products. That way, people know how to use the

product safely and effectively.

_________________________ is shown in many ways. One of the most common is in g/L. This unit

expresses the mass of solute in 1 L of the solution. For example, RoundupTM is a herbicide (a plant-

killing chemical). It is used to kill weeds before a crop is planted. RoundupTM is a solution of

glyphosate and water. The label says this product contains 7.0 g/L of glyphosate. This means that there

are 7.0 g of glyphosate in 1 L of the product.

THINK & WRITECan you think of a time where you added water to reduce the concentration of a product? Perhaps it was too concentrated for your liking, or you wanted the product to last longer.Come up with 4:

SolubilitySolubility describes how easily a solute will _____________ in a solvent to make a solution. When a

substance will dissolve in a solvent, we say that it is soluble. If a substance will not dissolve, it is said to

be insoluble.

As you can see from the photographs in Figure 3.6, substances such as oil and gasoline do not dissolve

in water. They are insoluble in water. Rocks have very low ____________ in water. In fact, the

solubility of rock is so low that only very sensitive tools can detect it dissolving. Sugar, on the other

hand, is very soluble in water. You can see sugar dissolve almost instantly.

Hummingbirds like sugar water with a concentration of 300 g/L. When you mix this solution, a lot of

sugar tends to remain ___________________ at the bottom of the container.

How Soap Works

While you are eating a hamburger, a glob of grease and mustard lands on your pants. How can you get

the stain out? For centuries, people have used soap for such tasks. Soap was originally made from

animal fat mixed with ashes from burned wood. When mixed together, these two substances form a

new substance that can dissolve oils, dirt, and other substances. Although today’s soaps are

manufactured from purified chemicals, they work the same way.

Soaps ____________ in water to form a cleaning solution. While grease and mustard are ___________

in water, they are soluble in a soap solution. The soap solution dissolves grease and other stains, so

they can then be rinsed away with the wash water.


3.3 - Separating MixturesAt the beginning of the chapter, you learned about the importance of having safe water to drink. People can die from _____________________ water even if it looks clean and clear.

Floods and industrial pollution are not the only sources of contamination. In the fall of 2000, many people in Walkerton, Ontario got sick from drinking the town’s tap water. Several people died. The problem was that run-off from nearby farms had contaminated the town’s water with deadly E. coli bacteria.

Usually, Canadian tap water is safe to drink because it has been treated.

•Dirty water (mechanical mixture) is _________________ to produce water that is clear.

•Chemicals such as ____________________ are added. These kill harmful bacteria.

•Other substances are added to _________________ dissolved chemicals (solution).

Separating SolutionsNow that you know how to make dirty water clear, how can you remove dissolved materials from it?

This is important because some water contains dissolved impurities.

THINK & WRITEWhat will happen if you placed a drop of salty water on a glass surface, then wait 24 hours? What will you see on the glass surface the next day?

Purifying Water

In Design & Do Investigation 3–C and Conduct an Investigation 3–D, you experimented with two

techniques for making water drinkable. Water treatment plants use similar methods to make sure that

the water you get is safe to drink.

In one method, technicians add alum to impure water. ______________, _______________, and tiny

dirt particles stick to the alum particles making them very heavy. These heavy particles sink to the

bottom, where they can be separated from the water.

Another step uses charcoal filters to remove dissolved impurities. The water that leaves the _________

is still not clean and safe to drink. Water treatment plants also add chlorine to drinking water. The

______________ kills any bacteria that are still present.

Distillation

Distillation is another way to get clean water. During this process, water is boiled and the steam

collected. As the steam cools, it condenses to form pure water. Anything that was dissolved in the

water is left behind. This includes solid particles such as salts and minerals, as well as other impurities

such as bacteria and viruses.

THINK & WRITECan you remember how to draw a sketch of distillation? Ask you teacher to draw and define.


WORK: Chapter 3 ReviewPage 56 (Questions 1-8)

Science 10-4UNIT A- “The Chemistry Unit” CHAPTER 4

4.1- Use Concentrated Solutions to Reduce Garbage How does your family buy orange juice? From the refrigerator section as a 1 L container? Or in the

freezer section in a small can that you thaw and mix? If you use frozen juice or juice crystals, you are

using a ______________________ product. Concentrated products have a lot of ___________ per

____________ of solvent. To make juice from concentrate, you need to ______________________.

The result is a tasty mix of solute and solvent.

Large containers of ready-made juice are the opposite. They have ___________________ per amount

of solution. Such solutions are called _________________ solutions. You can drink dilute juice right

from the package, or after adding a small amount of water. Dilute solutions have a _________ water

content. They require more _____________________ to hold this amount of water. The product could

be concentrated and packed in a smaller container, thus ____________________ packaging.

THINK & WRITECome up with a list of 4 or more items that you add water in order for them to make the substance a greater volume. (example: concentrated juice in a frozen can)

How Are Concentrated Products Made?

Like most of us, you probably use a lot of ___________________ products. These include instant

coffee, canned soups, soup mixes, packaged salad dressings, and ____________________ refried

beans for burritos. Think about these items. What do they all have in common? If you said they come

in small packages, you are right. And if you said they are dry or really thick, you are right again.

Concentrated products are dry or thick because they are made by ______________ some or all of the

_____________. Before using them, we need to replace that solvent.

In most cases, the solvent is _____________. In some cases, such as salad dressing, the solvent may be

oil or vinegar.

Waste Packaging

Every day, each person in Canada throws out about _____________ of trash. That is enough to fill

_____________ garbage trucks. Where does all that garbage come from? Paper and yard waste make

up a large percentage. So do food scraps, metals, glass, and ____________. About 30 percent of the

garbage in landfills is product packaging such as plastic wrap, cardboard, and tin. Not all packaging is

wasteful or undesirable. Some packaging protects food products from _______________ and spoilage.

Other packaging protects fragile products during shipping. Packages also provide valuable consumer

information, and some products have special child-proof packages to prevent children from being

poisoned. But _______________ across Canada would last longer if they were not filling up with so

much waste packaging. In Unit D, you will learn how you can reduce, re-use, and recycle to help. This

unit emphasizes the advantages of buying concentrated products.


4.2- Acids and Bases Vinegar cleans the stains from a coffee decanter. Soap slips out of your hand. Battery fluid will burn your skin and eat a hole in your clothes. _________________ eliminate ________________-.

What do these substances have in common? They belong to a group of substances called acids and bases.

• An acid is a ______________, sour-tasting substance that turns blue litmus paper red.

• A base is a _______________, bitter-tasting substance that turns red litmus paper blue.

• Substances that are neither acids nor bases are ______________. When you ________________ an acid or base, you make it neutral.

Properties of Acids and Bases

In Chapter 1, you learned that ________________ and __________________ properties allow

scientists to identify and classify matter. You already know that bases taste ____________ and acids

taste ____________. However, scientists do not rely on this property in order to identify acids and

bases. By repeated investigation, scientists have discovered other properties of acids and bases. This

allows substances that are too ______________ to touch or taste (such as ____________) to be

classified. Table 4.2 lists some properties of acids and bases.

THINK & WRITEUsing the textbook or your own knowledge, please list 8 examples of both acids and bases:

- -

- -

- -

- -

- -

- -

- -

- -

Identifying Acids and Bases

Scientists identify acids and bases using indicators. An ____________ is a natural substance that

changes _____________ in the presence of an acid or base. Some flowers are indicators. They change

colour depending on the ______________ of the soil. Lichens, cabbage juice, tea, and grape juice will

also change colour in the presence of an acid or base. The most reliable way to identify an acid or a

base is to use an indicator such as _____________, which is a dye made from lichen. Litmus paper is a

convenient indicator strip that has been treated with a weak solution of litmus. In the next

investigation, you will use litmus paper to identify common substances as either acids or bases.

A Scale for Classifying Acids and Bases

A substance’s pH tells you how acidic or basic it is. Knowing the pH of a substance helps you use it

___________ and _________________. Chemists have developed a scale that classifies how acidic or

basic substances are.

This pH scale classifies substances from 0 to 14.

• Acids have a pH of __________ than 7.

• Bases have a pH ____________ than 7.

• Substances that fall in the _____________ of the scale are neither acidic nor basic. They are neutral.


4.3- Acids and Bases in Action What makes a cake rise? How does an antacid cure heartburn? Why does baking soda keep your refrigerator smelling fresh? Learning about the reactions of acids and bases will help you answer each of these questions.

Baking — Many recipes call for sour milk. Cooks often sour milk by mixing __________ or lemon juice into it. When baking soda (___________) and sour milk (____________) mix, they quickly form a frothy mass. The reaction releases ___________________________ in the form of bubbles. This reaction makes pancake, cookie, and cake dough rise.

Cooking — In the past, cooks used _______________________ to find how best to cook various foods. Today’s chefs work in test kitchens to investigate the best cooking methods. Through careful study, they have found that the _________ of the cooking liquid affects the _____________ and _____________ of cooked vegetables. Vegetables cooked in an acidic mixture take longer to cook and do not soften. Those cooked in a basic mixture soften more easily. That is why chefs often add baking soda to dried beans before cooking them.

Health Care — Heartburn occurs when _______________ acid is produced in your stomach. To treat heartburn, you could take an ____________ tablet. Antacids are bases that help neutralize the acid in your stomach. When an acid and a base combine, they ______________ out each other’s properties. The result is a neutral substance. This chemical reaction is called neutralization.

Deodorizing — ____________________ helps baking soda remove ___________ from a refrigerator. Baking soda (a base) cancels out acidic food odours. Combining acids and bases can be useful. It can also be dangerous. In Chapter 1, you learned ____________ to mix bleach with an acid or base. That is because bleach forms ______________________ when mixed with either an acid (such as toilet bowl cleaner) or a base (such as ammonia).

Corrosion

Substances found near either end of the pH scale are ______________________. This means that they

can cause severe _____________ to skin and other body tissues. They can even eat through substances

such as ______________ or _____________.

Sulfuric acid can be found near one end of the pH scale, at about 0. Drain cleaner is near the other end.

Both are highly corrosive. How might being corrosive help a drain cleaner to work? What Affects

Corrosion?

Corrosion is the _______________________ of materials by chemical action. It is also known as

_________________. Oxygen is the primary cause of this chemical reaction. Substances such as acid

rain and salt speed up the process. Study the pictures and captions below to learn more about

corrosion.

Corrosion at Work

Corrosion accounts for many things, including the _______________ of _____________________.

When they come fresh from the mint, coins have bright silver or copper colours. With exposure to

__________, _____________, and other substances, they become _____________ and discoloured.

The colours they turn depend on the metals from which they were made. Silver turns black when it

corrodes. Few of today’s coins have much silver in them, but sterling silver does. Some silverware and

jewellery are made from sterling silver. That is why some good silverware turns ________. People

polish silver to remove the corrosion.


WORK: Chapter 4 ReviewPage 74-75 (Questions 1-14)

swensonspage.weebly.com€¦ · web view• msds — material safety data sheets provide detailed...

Documents