Chemistry in Motion: Unit 4 Hobbs

1. Bell Ringer: March 31, 2014

The oxidation number (charge) of an atom is show with a _______.a. Negative numberb. Positive Numberc. Superscriptd. Subscript

2. Bell Ringer: Tuesday, 04.01.14

What three items are needed for a Lewis structure? **If you missed the Unit 3 Test the last day to make it up is Thursday!!!! Study!

3. Bell Ringer: Wednesday, 04.02.14

In a chemical formula, like H2O, the number of each type of atom in the compound is shown by numbers called ___________.

a. Superscriptsb. Chemical symbolsc. Oxidation numbersd. Subscripts

4. Bell Ringer: 04.03.14

What is the correct chemical formula for magnesium oxide?

a. MgOb. MgO2

c. Mg2O2

d. Mg2O

***Naming Quiz TODAY!!!!*** TODAY is the last day to make up your UNIT 3 TEST!!!!

5. Bell Ringer: Friday, 04.04.14Balance the following equation:

___NH3 + ___ HCl ___ NH4Cl

11. Bell Ringer: 04.14.14Balance the following chemical equation:

__CaBr2 + __Na2CO3 __CaCO3 + __NaBr

12. Bell Ringer: 04.15.14

• What is the difference between the two mixtures below? Can you name each?

13. Bell Ringer: Wednesday, 04.16.14What is the difference between unsaturated, saturated, and supersaturated? (Think in terms of how much solute vs. solvent)

14. Bell Ringer: Thursday, 04.17.14Lenox made sweet tea for her family’s dinner that evening. She mixed the sugar in the tea, but not all of the sugar would dissolve. Has Lenox made an unsaturated, saturated, or supersaturated solution? Explain your answer.

16. Bell Ringer: Monday, 04.21.14The concentration of a solution that contains a large amount of solute in the solvent could be described as ___________.a. Concentratedb.Dilutec. Polard.Unsaturated

17. Bell Ringer: Tuesday, 04.22.14A substance that produces hydroxide (OH-) ions in water is a(n) a.Acid b.Basec.Hydrocarbond.Salt

BRING MONEY THURSDAY for the RELAY RALLY 4th BLOCK!!!

Thursday is BLACK and WHITE DAY!

18. Bell Ringer: Wednesday, 04.23.14• In a ________________ reaction, an acid and a base produce a salt and water.

• A. decomposition• B. dilute• C. neutralization• D. concentrated BRING MONEY

THURSDAY for the RELAY RALLY 4th BLOCK!!!

Thursday is BLACK and WHITE DAY!

DO NOT TOUCH ANYTHING, UNTIL I TELL YOU TO DO SO OTHERWISE, IT IS BOOKWORK for THE WHOLE BLOCK!

19. Bell Ringer: Thursday, 04.24.14• Tomato juice has a pH of 4. What substance would be needed to neutralize tomato juice?

• A. vinegar (pH 3)• B. pure water (pH 7)• C. soap (pH 10)• D. ammonia (pH 12)

BRING MONEY THURSDAY for the RELAY RALLY 4th BLOCK!!!

20. Bell Ringer: Friday, 04.25.14• Which solutions are most likely acids?

• A. 1 and 3• B. 2 and 5• C. 3 and 6• D. 4 and 7

Solution Effect on Blue Litmus

Effect on Red Litmus

1 None Turns blue

2 None Turns blue

3 None None

4 Turns red None

5 None Turns blue

6 None None

7 Turns red NoneOnce you finish, turn in BELL RINGERS and STUDY for your TEST, don’t act like you didn’t know you had a test, it’s been on the board for weeks and I have also been telling you all week!

Unit 3 Review

Two elements with the same number

of protons, but different number

of neutrons?

Unit 3 Review

What is the name of the elements along the stair

step line?

Unit 3 Review

Halogens are located in

which group?

Unit 3 Review

Differences between

alpha-beta-gamma?

Unit 3 Review

What are the general

properties of metals?

Unit 3 Review

Boron has a mass number of 11 and an atomic number

of 5. How many neutrons are in a

boron atom?

Unit 3 Review

How many electrons are in

the outer energy level of Group 17

elements?

Unit 3 Review

How many protons are in the nucleus of

Kr-81?

Unit 3 Review

•A(n) ________________ is a horizontal row in the periodic table.

Unit 3 Review

A vertical column of

elements is also referred to as what?

Unit 3 Review

When an atom is chemically stable,

how many electrons are in its outer energy level?

a. 0 b. 7 c. 4 d. 8

Make sure group numbers, oxidation numbers and valence electrons are CORRECT!!!!

Electron Dot Diagram/Lewis Structure

Electron dot diagram – a diagram or drawing where you use the element’s chemical symbol and valence electrons to show how atoms bond.

Electron Dot Diagram/Lewis Structure1) Find your element on the periodic table.2) Determine the number of valence electrons.3) This is how many electrons you will draw.• Find out which group (column) your element is in.• This will tell you the number of valence electrons

your element has.• You will only draw the valence electrons.

1) Write the element symbol.

2) Carbon is in the 4th group, so it has 4 valence electrons.

3) Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol.

C

Lewis Structures

Lewis Structures

C

On your worksheet, try these elements on your own:

a) Pb) Cac) Ard) Cle) Al

Useful Vocabulary• Subscript - is number next to the symbol of an

element. It represents how many atoms of a particular element is present in the chemical formula.

• Superscript – is the number above the symbol of an element. It represents the oxidation number (charge) of an atom/molecule.

• Binary compound – a compound composed of two elements.

Chemistry

• Chemical bond – attraction between atoms that allows the formation of chemical substances with two or more atoms.

Metallic Bonds

•Metal and metal bonded

Ionic Bonds

•Metal and nonmetal bonded to form a compound•Metal is giving its valence electron to the nonmetal•Example: NaCl

Covalent Bonds

•Nonmetal and nonmetal bonded to form a compound•The valence electrons will be shared•Example: N2O2

Bonding

Compounds• A compound is a substance composed of two or

more elements combined in a specific ratio and held together by chemical bonds.

• Familiar examples of compounds are water and salt (sodium chloride).

Ionic Compounds

The resulting electrically neutral compound, sodium chloride, is represented with the chemical formula NaCl.

The chemical formula, or simply formula, of an ionic compound denotes the constituent elements and the ratio in which they combine.

Naming Ions and Ionic Compounds

Balancing Equations

•Law of Conservation of Mass - in a chemical reaction, the mass of the products equals the mass of the reactants.

Balancing Equations: Parts of an Equation

•1. Reactants – come after the yield sign

•2. Products – come before the yield sign

•3. Coefficients – are used to multiply and occur in front of chemical formula

Balancing Equations

Types of Chemical Reactions• Synthesis: A synthesis reaction is when two or

more simple compounds combine to form a more complicated one. These reactions come in the general form of:

• A + B ---> AB• One example of a synthesis reaction is the

combination of iron and sulfur to form iron (II) sulfide:

• 8 Fe + S8 ---> 8 FeS

Types of Chemical Reactions• Decomposition: A decomposition reaction is the

opposite of a synthesis reaction - a complex molecule breaks down to make simpler ones. These reactions come in the general form:

• AB ---> A + B• One example of a decomposition reaction is the

electrolysis of water to make oxygen and hydrogen gas:

• 2 H2O ---> 2 H2 + O2

Types of Chemical Reactions• Single replacement: This is when one element

trades places with another element in a compound. These reactions come in the general form of:

• A + BC ---> AC + B• One example of a single displacement reaction is

when magnesium replaces hydrogen in water to make magnesium hydroxide and hydrogen gas:

• Mg + 2 H2O ---> Mg(OH)2 + H2

Types of Chemical Reactions• Double replacement: This is when the anions

and cations of two different molecules switch places, forming two entirely different compounds. These reactions are in the general form:

• AB + CD ---> AD + CB• One example of a double displacement reaction is

the reaction of lead (II) nitrate with potassium iodide to form lead (II) iodide and potassium nitrate:

• Pb(NO3)2 + 2 KI ---> PbI2 + 2 KNO3

How do we classify matter?Solute Atoms

Molecules

Matter

Substances

Elements

Compounds

Mixtures

Homogeneous

Heterogeneous

Solvent

Matter

• Matter is anything made of atoms and molecules.

• It is anything that has mass and takes up space.

How do we classify matter?• Atoms – is the

simplest form of matter

• Molecules - a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound

Substance• A pure substance

is a sample of matter with both definite and constant composition with distinct chemical properties (ex: fluorine)

How do we classify matter?• Elements – substance

that cannot be broken into two or more simpler substances (ex: mercury)

• Compounds - is a substance formed when two or more chemical elements are chemically bonded together. (ex: NO2)

Mixture• a mixture is

when two or more substances are mixed together but not combined chemically.

How do we classify matter?• Mixtures

• Homogeneous - is simply any mixture that is uniform in composition throughout, therefore the different parts cannot be seen. (examples: koolaid, lemonade, sweet tea)

• Heterogeneous - is made of different substances that remain physically separate, so the different parts are seen.

(ex: trail mix, salads, cereal)

Mixtures• Solute – is the

smaller portion of the mixture and the part that is being dissolved.

• Solvent – the bigger portion of the mixture and the part doing the dissolving.

Mixtures• Mixtures

• Homogeneous - is simply any mixture that is uniform in composition throughout, therefore the different parts cannot be seen. (examples: koolaid, lemonade, sweet tea)

• Heterogeneous - is made of different substances that remain physically separate, so the different parts are seen.

(ex: trail mix, salads, cereal)

Mixtures• Solute – is the

smaller portion of the mixture and the part that is being dissolved.

• Solvent – the bigger portion of the mixture and the part doing the dissolving.

Solutions

• Reading Essentials Book• Page 378-382• On your own paper• Respond to questions in the margins, except DO NOT DO THE FOLDABLE!

Solutions

• A solution is a mixture of two or more substances, aka homogeneous mixture.

Solubility• Saturated: describes a

solution that has dissolved the maximum amount of solute

• Unsaturated: describes a solution that has less than the maximum amount of solute dissolved

• Supersaturated: describes a solution that has dissolved more than the maximum amount of solute

Solutions• Dilute - make (a

liquid) thinner or weaker by adding water or another solvent to it.

• Precipitate – a substance is deposited in solid form from a solution.

Solutions• Scientist use the axiom

“LIKE DISSOLVES LIKE”• Nonpolar solute

dissolves in a nonpolar solvent

• Polar solute dissolves in a polar solute

• Electronegativity affects solubility of solutions. If you have nonpolar and polar, your solute will not dissolve.

• As you go from left to right across the periodic table electronegativity increases.

Can a solution conduct electricity? • Electrolytes are

substances that conduct electricity when dissolved in water.

• Nonelectrolytes are substances that don’t conduct electricity when in these states.

• Examples: NaCl and Sucrose

What affects solubility rate of solute?• A. Temperature

– heat vs. room temperature or cold

• B. Surface Area – compare small area to large area

• C. Agitation – stirring, shaking

Solubility Curve

Solubility Curve• What

temperature would a solution need to be to dissolve 110kg of solute?

Solubility Curve• If a solution had

100kg of solute dissolved in 80°C, is it a saturated solution?

Solubility Curve

• Which solute is most soluble at 10°C?

• How much NaCl can be dissolved in 90°C solvent?

Solubility Curve: Gases• Affected by:

• Temperature• Pressure

• Inverse relationship

• Ex: O2 and lake

Create a foldable: Acids and Bases

• Need 2 pieces of paper• Fold one into the other,

create four flaps, then staple the top two corners

• 1. How Litmus paper/pH paper works

• 2. List of household Acids and Bases and pH

• 3. pH scale with numbers and labels (weak acid, weak base, neutral, strong acid, strong base)

• 4. Acids and Bases Facts

Acids and Bases starts on page 694

Once you finish, start on page 470 1-20

Litmus paper

•Changes colors in the presence of acids and bases

•Litmus paper can be either blue or red

•ABR – acids turn BLUE litmus paper RED

•BRB – bases turn RED litmus paper BLUE

pH paper• pH paper is blotting paper that has been

treated with a mixture of different indicators. Each indicator changes color over a different pH range.

pH scale

• pH is a measure of how acidic or basic a solution is.

•The pH scale ranges from 0 to 14. • Acidic solutions have

pH values below 7• A solution with a pH of 0

is very acidic.• A solution with a pH of 7

is neutral.•Pure water has a pH of 7. •Basic solutions have pH values above 7.

pH scale•A change of 1 pH unit represents a tenfold change in the acidity of the solution. •For example, if one solution has a pH of 1 and a second solution has a pH of 2, the first solution is not twice as acidic as the second—it is ten times more acidic.

Household Acids

• Acids0 - Hydrochloric Acid (HCl)1.0 - Battery Acid (H2SO4 sulfuric acid)2.0 - Lemon Juice2.2 - Vinegar3.0 - Apples4.5 - Tomatoes6.6 - Milk

Household Bases

• Bases7.4 - Human Blood8.3 - Baking Soda (Sodium Bicarbonate)10.5 - Milk of Magnesia11.0 - Ammonia12.4 - Lime (Calcium Hydroxide)13.0 - Lye14.0 - Sodium Hydroxide (NaOH)

Acid & Base Facts: What is an acid? • An acid is a solution that has an excess of H+ ions. It comes from the Latin word acidus that means "sharp" or "sour".

• The more H + ions, the more acidic the solution.

Acid & Base Facts: Properties of an acid…

• Tastes Sour• Conduct Electricity• Corrosive, which

means they break down certain substances. Many acids can corrode fabric, skin, and paper

• Some acids react strongly with metals

• Turns blue litmus paper red

Acid & Base Facts: Uses of Acids• Acetic Acid =

Vinegar• Citric Acid = lemons,

limes, & oranges. It is in many sour candies such as lemonhead & sour patch.

• Ascorbic acid = Vitamin C which your body needs to function.

• Sulfuric acid is used in the production of fertilizers, steel, paints, and plastics.

• Car batteries

Acid & Base Facts: What is a base?• A base is a solution that has an excess

of OH- ions. • Another word for base is alkali.• Bases are substances that can accept

hydrogen ions

Acid & Base Facts: Properties of a base• Feel Slippery• Taste Bitter• Corrosive• Can conduct electricity. (Think alkaline batteries.)

• Do not react with metals.

• Turns red litmus paper blue.

Acid & Base Facts: Uses of Bases

• Bases give soaps, ammonia, and many other cleaning products some of their useful properties.

• The OH- ions interact strongly with certain substances, such as dirt and grease.

• Chalk and oven cleaner are examples of familiar products that contain bases.

• Your blood is a basic solution.

Acid & Base Facts: Acid-Base Reactions• A reaction

between an acid and a base is called neutralization. An acid-base mixture is not as acidic or basic as the individual starting solutions.

• Acid + Base salt + water

Acid & Base Facts: Acid-Base Reactions

• Each salt listed in this table can be formed by the reaction between an acid and a base.

Acids vs. Bases Lab • You will be in groups of 2-3 people • Each group will have ONE answer sheet• Each group will have one set of unknowns (one

well plate)• Each group will have one set of test papers (red

litmus paper, blue litmus paper, and pH paper)• Each UNKNOWN is to be tested with EACH

PAPER!!!! (so test it once with the red litmus paper, once with the blue litmus paper, and once with pH paper and RECORD your FINDINGS AFTER EACH on your answer sheet)

• Each group will need a paper towel, number the paper towel so you can place each unknown’s test strips in their respective place.

AFTER the LAB

•CLEAN UP YOUR MESS, I AM NOT YOUR MAID!

• Complete page 470 1-20, will be graded for accuracy and completion

• Complete page 690 1-18, will be graded for accuracy and completion

Unknowns

• 1. lemon juice• 2. coffee creamer• 3. coke• 4. green tea• 5. dish soap• 6. coconut milk• 7. ammonia• 8. windex• 9. lysol cleaner• 10. coffee

TODAY: 04.24.14

•Complete page 470 1-20, will be graded for accuracy and completion

•Complete page 690 1-18, will be graded for accuracy and completion

•REVIEW for TEST

04.25.14: TEST DAY

• Once finishing YOUR TEST, turn in your test to the lab table (stack for scantrons (A/B), stack for tests (A/B))

• Turn in your textbook to Chapter 7 (page 192-199), read the section and answer questions 1-5, bonus points if you answer question 6

• NO TALKING UNTIL ALL TESTS and WORK IS TURNED IN!