chemistry 40s - welcome to robynmercurypunk.net/chem 40s module 1 part 1 2013 text... · web...

RIVER EAST TRANSCONA SCHOOL DIVISION

ADULT EDUCATION PROGRAM

Teacher: Robyn Mitchell

2010 1

RETSD Adult Education Program CHEM 40S

CHEMISTRY 40S

INTRODUCTION

Rationale

A general education in science should make it possible for people to appreciate the worthiness of the scientific enterprise and to use its achievements for attacking contemporary problems as well as designing the future we seek.

Course Structure

The course was built around five modules, each divided into several lessons.

Core:

Module 1: Fundamentals of Chemistry (Review of Grade 11) and Atomic Chemistry

Module 2: Aqueous Reactions

Module 3: Reaction Rate (Kinetics) and Chemical Equilibrium

Module 4: Ionic Equilibria: Acids and Bases

Module 5: Oxidation and Reduction

Assessment

Module Tests: 5 @ 6 marks each: 30 marks

Labs: 25 marks

IN CLASS ASSIGNMENTS & quizzes 10 MARKS

Final Exam: 35 marks

___________

Total: 100 marks

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Laboratory Activities and Safety Standards

Laboratory Safety: You must complete the “Lab Safety Mini Module” package. There is also a lab safety link on my site: mercurymasterpunk.ca, Chemistry 40S link, at the top of the page.

You must take the Lab Safety work seriously, and keep safety in mind at all times while working in the laboratory.

The prevention of accidents in a laboratory is the responsibility of every individual who enters it.

Text (available for rent but not required):

Chemistry: The Study of MatterDorin, Demmin, GabelPrentice Hall, 1989

Please note that there are three other textbook resources for Chemistry available at the Transcona Learning Centre. Please ask one of the teachers if you wish to supplement your reading with one of these resources. If something just isn’t making complete sense as you read through your material, consult one of these alternate sources, and you will often find that simply reading another author’s words can clarify things for you.

TEST PREPARATION

When preparing for a test, it is recommended you:

read through everything in your module as you read, re-do any questions or problems that you are not

100% sure about as you read, make notes on everything you do not already know go over your notes and try to reduce them make a concept map of the concepts and terminology of the module review anything on my website that we looked at in class or that was

assigned for homework:

mercurymasterpunk.ca

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CHEMISTRY 40S

MODULE 1 -- FUNDAMENTALS OF CHEMISTRY & ATOMIC CHEMISTRY

You will need some loose leaf in your binder along with the modules that are handed out to you. You should use the loose leaf to (1) jot down important points as you work through many of the modules, and (2) write out answers to the assignments contained in the modules. It is imperative that you do all the questions and assignments as you work through the course -- your understanding of the material will be deepened by it, and you will develop and sharpen your problem solving skills, which are important attributes in science courses.

This module is divided into two parts: the first is about the fundamentals of chemistry, and the second is Atomic Chemistry.

PART 1 -- FUNDAMENTALS

This part of the module contains reading and assignments not specifically outlined in the Foundation for Implementation for Chemistry 40S. The assignments are extremely important for adult learners because they will build your skills and knowledge in areas you may not have encountered for a while, depending on how long ago you took Chemistry 30S. You need these basics in order to fully understand many of the concepts in the Chemistry 40S course. Please allow plenty of time to review these concepts, as they are critical.

LESSON 1 -- S.I. UNITS

There are International System (S.I. – commonly called metric) units for all types of measurement. Go here to see common ones and less common ones as well: http://physics.nist.gov/cuu/Units/units.html

In chemistry, the amount of a substance is expressed in moles, and temperature is often expressed in kelvin (K), rather than C, which is a non-SI unit that is still used in many chemistry books and articles. Read the section below on SI and answer the questions.

How To Write SI Units

Rules for Writing SymbolsOne of the main advantages of SI is that there is a unique symbol for each unit. Because these are international symbols and not abbreviations they do not change for different languages. You will find it easier and in most cases faster to use the SI symbol instead of writing the name of the unit in full.

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http://physics.nist.gov/cuu/Units/units.html


The basic rules for writing symbols are:1. The symbols are always printed in upright type, regardless of the type face used in

the rest of the text: ie., m g C s

2. Symbols are written in lower case, except when the unit name is derived from a proper name:m for metre; s for second; N for newton: A for ampere; (exception—L for litre).

3. Prefix symbols are printed in upright type without spacing between the prefix symbol and the unit symbol:kg for kilogram; km for kilometre

Note: When the names of the units which derive from a proper name are written out in full, only Celsius takes a capital.

4. Symbols are never pluralized: 45 g (not 45 gs)

5. Names and symbols should not be mixed. N m or newton metre, but not N metre or newton m.

6. Never use a period after a symbol, except when the symbol occurs at the end of a sentence.

7. Always use a full space between the numeral and the symbol: 45 g (not 45g)

Exception: When the first character of a symbol (for non-SI unit) is not a letter, no space is left:32C (not 32 C or 32 C)

8. Symbols should be used in conjunction with numerals instead of writing out the unit names; when no numerals are involved, unit names should be written out.10.0 g/mol not 10.0 grams / mole (ten grams per mole is correct).

9. The product of two or more units in symbolic form is indicated by a dot. It is recommended that the dot be positioned above the line to distinguish it from a decimal marker dot on the line.eg. kgms2

The rules for writing numbers are:

1. Use decimals, not, fractions. eg., 025 g (not ¼ g)

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2. Use a zero before the decimal marker in numerical values less than one:eg. 0.45 g (not .45 g)

3. Use spaces to separate a long number into easily readable blocks of three digits with respect to the decimal marker.eg. 32 453.246 072 5 Exception: A space is optional with a four-digit number: 1 234 or 1234 – both are correct.

4. As a decimal marker both the point and the comma are widely used in the world today. Metric Commission Canada’s policy is to use the comma in French-language documents and the point in English-Language documents.

ASSIGNMENT 1

Correct the SI error(s) in the following statements:1. Michael bought 2 kilos of hamburger.

2. The recipe called for 1.0 ML of vanilla and 100 cc. of milk.

3. Jill bought 6.0 liters of gasoline for her 250 c.c. motorcycle.

4. The car accelerated from rest to 100 Km. per hour in 10 sec.

5. The weight of 1 Ml of water is exactly 1 gms.

6. The package was marked as containing 500 Gm. of spaghetti.

7. The height of the precipitate in the test tube was 2-1/2c. m.

LESSON 2 – Elements and Compounds

What is an element? All matter on earth is composed of elements or a combination of the elements – 88 of which are naturally occurring, and 24 of which are made in laboratories. An element is a substance that cannot be broken down into a simpler substance by chemical or physical means. It is composed of atoms all having the same atomic number.All the elements are found on the Periodic Table – you will be given one in class. At the top there is a key using carbon as an example. The atomic number, which represents the number of protons in the atom’s nucleus, is shown in the upper left corner of the periodic table we are using. An oxygen atom has 8 protons in its nucleus, and it has 8 electrons that “orbit” around the nucleus. The number of protons will equal the number of electrons in an atom, as protons are positively charged particles, and electrons are

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negatively charged particles, and whole atoms are neutral (have no net charge). The atomic mass is shown in the bottom left corner, and represents the sum of the number of protons and the number of neutrons in an atom.

There is a good periodic table tutorial on the Chem 40S page. This is the URL: http://www.youtube.com/watch?v=fLSfgNxoVGk&safe=active

In the periodic table, the elements are arranged in rows in order of increasing atomic number. Each horizontal row is called a period, and each vertical column is called a group or family. The elements in a group all have similar physical and chemical characteristics.

Look at your periodic table or see one at ptable.com.

Metals are elements that are shiny, ductile (can be pulled into wires), malleable (can be hammered into thin sheets), solid at room temperature (except Mercury), and are good conductors of heat and electricity. They also form positive ions (discussed later), whereas nonmetals form negative ions. Nonmetals lack the characteristics listed above for metals, and they exist as gases, liquids, and solids at room temperature.

Groups of Elements – groups are the columns of the periodic table. They are numbered left to right from 1 – 18. You must know where on the periodic table each of the following families are located: the noble gases, halogens, alkaline earth metals, and alkali metals

Chemical changes take place all around you, and within you. Jewellery made of silver reacts with sulfur in the air to form a blackish, unattractive coating called silver sulfide. Strike a match, and it burns in the air to form colorless gases. Egg white changes from a clear liquid to a white solid when heated. New substances are formed in all these instances. The original substances are called the reactants, and the resulting substances that are different from the reactants, are called products of the reaction.

We can express chemical reactions by using the symbols for the elements and the formulas for compounds, as in 2 H2(g) + O2(g) → 2 H2O(g), the most common way in chemistry, or we can use a word equation (a little more tedious):

A word equation is a chemical reaction expressed in words rather than chemical formulas.

The same reaction can be described as: hydrogen gas + oxygen gas → steam

Chemical Formulas

If you need to brush up on how to write chemical formulas, and need a review of naming and classifying, please go to my website, mercurymasterpunk.ca, and click on the Chem

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http://www.youtube.com/watch?v=fLSfgNxoVGk&safe=active


30S page, scroll about halfway down, and open the word file under Module 3 heading – the link is entitled “Module 3, Lesson 2 – Writing Formulas and Naming Compounds”. Another good link for instructions and practice can be found on the Chem 30S page and is called “the Naming Compounds Handout” in bright pink font. If you want to try to tackle it without, just do the assignment below and the practice sheets that follow this section of the module.

ASSIGNMENT 2: Recap Questions

1. What is a chemical equation?2. Differentiate between reactants and products3. How would you properly say the following word equation?

a. Copper + silver nitrate silver + copper nitrate4. In the above equation, which are the reactants, and which are the products?

5. Write formulas for each of the following:a. iron (II) chloride (the II means the iron forms an ion with a charge of +2)b. iron (II) sulfidec. iron (III) sulfide (iron can also form an ion with a charge of +3)d. lead (IV) iodidee. tin (II) oxide

6. Give the name and the symbol of each of the ions present in each compound:a) NaCl b) BaBr2 c) CaSO4 d) KCl e) CdCO3

f) CuCl2 g) SnCl4 h) FeO

7. Write formulas for each of the following:a) Iron (II) sulfide b) iron (III) sulfide c) calcium carbonate

Here is a site with practice writing word equations, along with an answer key: http://www.chem.missouri.edu/chem1310/written%20chemical%20equations.pdf

LESSON 3 --Balancing Equations and the Mole

Because atoms, as mass, are conserved in chemical reactions, there will always be the same number of atoms of each element on both sides of an equation. Chemists express this equality by writing balanced equations. A balanced equation is one in which the number of atoms of each element in the reactants (before the reaction) is equal to the number of atoms of that element on the products side (after the reaction).

ASSIGNMENT 3:

A> Tell how many atoms of each element are present in each of the following:i. 5NH3

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http://www.chem.missouri.edu/chem1310/written%20chemical%20equations.pdf


ii. 4Ca(OH)2

iii. 3BaSO4

B> Do the practice balancing sheet.

CHEMISTRY 40SSKILLS PRACTICE – BALANCING EQUATIONS

Balance the following equations:

1. KClO3 KCl + O2

2. SF4 + H2O SO2 + HF

3. FeS + HCl H2S + FeCl2

4. BaCl2 + (NH4)2SO4 BaSO4 + NH4Cl

5. C2H2 + O2 CO2 + H2O

6. KClO3 KCl + O2

7. SF4 + H2O SO2 + HF

8. FeS + HCl H2S + FeCl2

9. Cl2 + NaBr Br2 + NaCl

10. CaC2 + H2O C2H2 + Ca(OH)2

11. Fe2O3 + C Fe + CO

12. Ca(OH)2 + HCl CaCl2 + H2O

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C>FORMULAS & BALANCING

For each of the following word equations, (1) determine the chemical formulas of each compound (2) write out the chemical equation, and then (3) balance the equation.

1. Silver nitrate + potassium sulfate silver sulfate + potassium nitrate

2. Hydrogen iodide + oxygen iodine + water

3. Iron (III) chloride + potassium hydroxide potassium chloride + iron (III) oxide + water

4. zinc + sulfuric acid zinc sulfate + hydrogen

For extra practice with balancing equations and writing formulas, look to the end of this section of the module.

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The MoleWe have a textbook (or my Chem 30S modules as mentioned earlier, accessible on my Chemistry 30S page, module 3) if you need to review the mole concept. Try these questions and if you are lost, ask me for the required reading to back up a bit and refresh.

MOLE ASSIGNMENT1. What is the difference between atomic mass and molar mass of an element?2. What is the molar mass of the following elements?

a) Fe b) Ca c) Mg d) B3. What is the mass of one atom of:

a) Zn b) P c) Cl4. What is the molar mass of Mg(NO3)2 ?5. What is the molar mass of ammonium sulfate, (NH4)2SO4?6. What is the mass in grams of 1 mole of carbon atoms?7. a) What is the mass of 1 mole of oxygen atoms?

b) How many atoms are present in 2 moles of oxygen atoms?8. a) What is the mass of 4 moles of nickel?

c) How much does 0.5 mol of nickel weigh?9. What is the mass of one mole of Al2S3?10. What is the mass of 3 moles of NaOH?11. How much does 0.005 moles of Fe2O3 weigh?

If you had trouble with the above, read Section 8 – 2, 8 – 3, 8 – 4 and 8 – 5 (Page 176 – 184 of textbook). As an alternate source, try reading pages 219 – 235 in Zumdahl, Introductory Chemistry: A Foundation. This book is for use at the TALC. See your instructor to borrow it on site.

Expressing Concentrations of Solutions

We often need to know exactly how much of a substance is in an aqueous solution (in water) because many chemical reactions in our bodies and in industry take place in water solutions. So the way that we express concentrations in our chemistry class is MOLARITY. When you see a capital M, you need to know what it means. You will see a lot of them in this course.

Molarity = moles of solute/ L of solution

A 1 molar solution (abbreviated 1M) has 1 mol of solute in every 1 L of solution. For example, a 1 M solution of sucrose (common sugar) has 1 mol of sucrose molecules in every 1 L of water.

Also, a 1 M solution of NaCl has 1 mol of formula units (the appropriate chemical name for the tiniest pieces of an ionic compound) in 1L of water. Because a formula unit of NaCl contains one sodium ion and one chloride ion, a 1 M solution of NaCl contains 1 mol of sodium ions and 1 mol of chloride ions in every L of water.

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Sample question: If a sugar solution has a concentration of 0.15 M (this means in ONE LITRE there would be 0.15 moles of sugar), and you only have 200 mL of it, how many moles of sugar is dissolved in it?

Remember C= n/V ?

Where C = concentration (M), n = number of moles of solute, and V = volume

0.15 M = n/ 0.2 L

Cross multiply and solve for n0.15 x 0.2 = 0.03

There are 0.03 moles of sugar in it.

Types of Chemical Reactions

The following section on types of reactions is taken from the Addison-Wesley Chemistry

Lab Manual:

There are five general types of chemical reactions: combination reactions, decomposition

reactions, single-replacement reactions, double-replacement reactions, and combustion

reactions. Most common chemical reactions can be classified as belonging to one of

these categories. Following is a description of each type:

1) Combination ReactionsCombination reactions are reactions in which two or more substances combine to form a

single product. The reactants may be elements or compounds, but the product is always a

single compound. An example of a combination reaction is the reaction of sulfur trioxide

and water to form sulfuric acid.

SO3(g) + H2O(l) H2SO4(aq)

2) Decomposition ReactionsDecomposition reactions are reactions in which a single substance breaks down into two

or more simpler substances. There is always just a single reactant in a decomposition

reaction. An example of a decomposition reaction is the breakdown of calcium carbonate

upon heating.

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CaCO3(s) + heat CaO(s) + CO2(g)

3) Single-Replacement Reactions

Single-replacement reactions are reactions in which an element within a compound is

displaced by a separate element. This type of reaction always has two reactants, one of

which is always an element. An example of a single-replacement reaction is the reaction

of zinc metal with hydrochloric acid:

Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g)

4) Double-Replacement Reactions

Double-replacement reactions are reactions in which a positive ion from one ionic

compound exchanges with the positive ion of another ionic compound. These reactions

typically occur in aqueous solution and result in either the formation of a precipitate, the

production of a gas, or the formation of a molecular compound such as water. An

example of a double-replacement reaction is the reaction that occurs between aqueous

silver nitrate and aqueous sodium chloride. A precipitate of solid silver chloride is

formed in this reaction.

AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq)

5) Combustion Reactions

Combustion reactions are reactions in which an element or a compound reacts rapidly

with oxygen gas to liberate heat and light energy. Commonly, the compounds combining

with oxygen in these reactions are hydrocarbons, compounds consisting wholly of

hydrogen and carbon. The well-known combustible fuels, kerosene and gasoline, for

instance, are hydrocarbon mixtures. The complete combustion of a hydrocarbon yields

carbon dioxide and water as the reaction products. If insufficient oxygen is available,

combustion will not be complete and carbon monoxide and elemental carbon may be

obtained as additional products of the reaction. An example of a combustion reaction is

the burning of methane gas to give water (in the form of steam), carbon dioxide, heat, and

light.

CH4(g) + 2O2(g) CO2(g) + 2H2O(g) + heat + light

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LESSON 4 -- Using Scientific Notation -- Expressing the Very Large and the Very Small

Scientists and students of science must often deal with numbers that are extremely large or extremely small. For example, one extremely large number is the number of particles (atoms or molecules) in a mole of substance, a.k.a. Avogadro’s number: 602 000 000 000 000 000 000 000 -- also written as 6.02 x 1023. This is a number so large it is nearly impossible to truly comprehend. Following are some comparisons:

18 mL of water (H2O) = 1 mole OR = 6.02 x 1023 molecules

If these particles were grains of sand rather than molecules, they would cover Canada 7 cm deep.

If these particles were marbles, they would cover the earth 80 km deep. If each particle were a loonie, you could spend a billion dollars a day for more

than a trillion years.

An example of an extremely small number is the wavelength of red light, which is 6.10 x 10-7 m, or 0.000000610 m or 0.000610 mm. If this number and Avogadro’s number were not written the way they most commonly are, which is in scientific notation, people that deal with these numbers would be wasting our precious time counting the zeros that separate the figures from the decimal point. To avoid useless time wasting, a method of writing very large and very small numbers was invented. It is called “scientific notation.”

The rules for writing numbers in scientific notation are:1. The first figure is a number from 1 to 9.2. The first figure is followed by a decimal point and then the rest of the figures.3. The first figure is then multiplied by the appropriate power of 10 that would result

in the decimal being in the correct place.

Here are some examples:

425 = 4.25 x 102 -- this means multiply 4.25 by 10 twice.We use a decimal point after the 4, but t o make 4.25 equal to 425, we must multiply by 100 (10 x 10), or 102.

36000 = 3.6000 x 104 -- multiply 3.6 by 10 four timesPlace the decimal after the 3, and multiply by 10 000 (10 x 10 x 10 x 10), or 104.

0.00098 = 9.8 x 10-4

This time, after putting the decimal point after the 9, we multiply by 1/10 000, or 10-4. You can also think of this as dividing by 10 000.

0.0135 = 1.35 x 10-2

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Decimal point after the 1, and multiplication by 1/100, or 10-2.

ASSIGNMENT 4

Express each of the following numbers using scientific notation:

1. 3252. 6 587 234 0003. 3 621.4564. 240.0005. 96 4006. 0.507

7. 0.004876098. 0.008919. 178 40010. 0.0732

Express the following in regular decimals:

11. 4.58 x 10-4

12. 3.08 x 107

13. 1.25 x 10-1

14. 9.023 x 104

Calculators and Scientific Notation

The problem many students have with using scientific notation is that they try to enter it

into their calculators exactly the way it is written. However, a number such as 1.56 x 106

should be entered as 1.56, then press the exponent key, which is usually labeled “EE” or

“EXP” and then the number to which 10 is raised (in this example, 6). DO NOT use your

multiplication key to enter scientific notation unless you are multiplying two numbers

together. For more assistance on how to do mathematical operations with your scientific

calculator, see your instructor.

SOME COMMON SYMBOLS:

[ ] means concentration. For example, [NaOH] means “the concentration of sodium hydroxide”

M means moles per litre. For example, 1.0 M means that there is 1 mole of substance dissolved in 1 litre of water.

e.g. [NaOH] = 1.0 M

(become familiar with the above notation; you will be seeing a lot of it in the near future.)

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References:

Baldwin, George. Senior 4 Chemistry – A Foundation for Implementation. Winnipeg, MB: Manitoba Education and Training, 1998.

Matchullis, Lynda. Senior Years Science Teachers’ Handbook. Winnipeg, MB: Manitoba Education and Training, 1997.

Wilbraham, Antony C., Dennis D. Staley, Candace J. Simpson, and Michael S. Matta. Chemistry Laboratory Manual – Teacher’s Edition. Menlo-Park, CA: Addison-Wesley Publishing Company, 1990.

Zumdahl, Steven S. Introductory Chemistry – A Foundation (4 th Edition) . Boston, MA: Houghton Mifflin Company, 2000.

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CHEMISTRY PRACTICE

WRITING CHEMICAL FORMULAS

Determine the chemical formula for the following pairs of ions:

1. Na+ and CO32-

2. Fe3+ and NO3-

3. Li+ and O2-

4. K+ and MNO4-

Determine the charges on each of the following ions (use the ion chart on page 155 of your text), and then write the formulas for the compounds formed by their reaction:

5. Rubidium and chloride

6. potassium and sulfide

7. magnesium and bromide

8. nickel and sulfate

9. berillium and hydroxide

10. Zinc and sulfite

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Given the following compound names, write their chemical formulas:

11. strontium nitrate

12. lead (II) nitrite

13. cobalt chloride

14. nickel phosphate

15. cadmium cyanide

16. copper (II) sulfide

17. aluminum chromate

18. ammonium chloride

19. copper (I) chlorate

20. sodium bicarbonate (a.k.a. sodium hydrogen carbonate)

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