Chapter 3

Matter – Properties and Changes

Warm –Up (for collection!)

These are directly from the podcasts…if you did the homework you should be a pro!! If you set these up correctly you’ll get a 100 homework grade.

• How many km are there in 85,412 cm?

• A cube of solid material has a mass of 13.6 g and a side length of 2.2 cm. Does it float in water??

Matter

• Substance – pure, uniform and unchanging composition

Examples:

Salt NaCl

Water H2O

Is sea water a pure substance?

Salt Pond BaySt. John USVI

During the dry season this is what you

will find when visiting Salt Pond Bay.

The bay is connected to the ocean during

rainy seasons.

What happens at Salt Pond Bay?

Why does the salt crystallize on the shore

and on exposed rocks?

States of Matter

• Describe the matter inside your container.

What is the shape?

Does it take up all the space in the container?

Can you squeeze it and reduce the volume?

States of Matter

• Solids –

Definite shape

Definite volume

Solids can be soft like wax or hard like rocks

Examples: wood, iron, paper, sugar

States of Matter

• Liquids –

Takes shape of container

Definite volume

Liquids flow and the particles are not rigidly held in place

Examples: water, blood, mercury

States of Matter

• Gases –

Takes shape of its container

Takes volume of its container

Gas particles are far apart and are easily compressed

Examples: oxygen, carbon dioxide, helium

Vapor is a gaseous state of something that is a solid or liquid at room temperature

Physical Properties of Matter

Extensive IntensiveIf I cut my object in half,

this property would be the same

If I cut my object in half,

this property would change

Mass

Volume

Length

Color

Density

Taste

Smell

These are all categorized as PHYSICAL properties

Chemical Properties of Matter

Ability to CHANGE and REACT with other matter

Rusting

Burning

Reactivity with Acids or Bases

Chemical or Physical Properties??

• Fe + O2 Fe2O3 (RUST!)

• Iron is more dense than Aluminum.

• Magnesium burns brightly when ignited.

• Sugar dissolves in water.

• Sugar burning.

• Mercury is a liquid at room temperature.

• Chlorine has a green colored flame.

• Liquid water cannot reach temperatures higher than 373 K.

Conservation of Mass

• Matter is neither chemically created nor destroyed

Whatever mass you start with, you end up with!

Mass of Reactants = Mass of Products

Bread + Cheese Grilled Cheese Sandwich

1 g + 0.5g 1.5g

Practice Problems

• In the complete reaction of 22.99g of sodium with 35.45 g of chlorine, what mass of sodium chloride is formed?

• A 12.2 g sample of X reacts with a sample of Y to form 78.9 g of XY. What is the mass of Y that reacted?

Warm – Up!• Which of these measurements was made with the most precise measuring device:

8.1956 m, 8.20 m, 8.196 m and why?

• A common brand of cough syrup comes in a 4-fl oz bottle. The active ingredient in the cough syrup is dextromethorphan. For an adult, the standard dose is 2 tsp, and a single dose contains 20 mg of dextromethorphan. If 1 fl oz = 29.6 mL and 1 tsp = 5.0 mL, how many grams of dextromethorphan are contained in 1 bottle?

Lab Wednesday

Statement of Problem:Given a rectangular piece of Aluminum foil, a ruler, a balance and knowing the density of Aluminum = 2.7g/cm3, determine the thickness of aluminum foil.

Pre-lab Assignment:

Write out the statement of problem in your lab notebook, relevant background information, AND a planned procedure.

YOU MUST COME TO LAB WITH PRE-LAB COMPLETE

Warm –Up!

Slope = 4.57

0

5

10

15

20

25

30

0 1 2 3 4 5 6 7

Density Graph

Volume (mL)

Mass (

g)

1. On a density graph, what does the slope represent?

2. What is the equation for the line (y=mx+b)?

3. If the actual density is 4.32. g/cm3 and the slope is

4.57 g/cm3 , what is the percent error on the slope??

Agenda

• Warm – Up

• Test Prep – what to expect and your questions

• Determination of the Thickness of Aluminum Lab

– Accepted thickness of foil = 2.33 x 10-3 cm

Exam Info!

• Thursday (tomorrow)

• Metric Conversions

• Density

• Dimensional Analysis

• Graphing and Slope

• Significant Figures

• Accuracy and Precision

• Scientific Notation

Review Sheet covers ALL topics!!!After School around 2:45

Warm – Up!4 partners of students were asked to find the density of an unknown piece of metal. Their findings were:

Group 1 – 11.256 g/cm3

Group 2 - 11 g/cm3

Group 3 - 11.53 g/cm3

Group 4 - 11.3 g/cm3

1. Which group was the most precise?

2. What was Group 3’s error (accepted density of Pb –11.34g/cm3 ?

3. Is density an intrinsic or extrinsic property. Explain.

Warm – Up!

• Physical or Chemical change??

– Rusting

– Freezing water

– Crushing an aluminum can

– Fruit ripening

• If 3g of iron reacts with 4 g of oxygen how many grams of rust is produced?

– Can you write out the chemical equation??

• Name 1 instrinsic and 1 extrinsic property

Agenda

• Warm – up!

• Review States of Matter and properties of matter.

• Create a chart relating forms of matter (substances, mixtures etc.) to see relationships and categories.

• Elements!! and percent mass calcs of compounds.

Periodic TableGroups

Periods

Percent By Mass Calculations

What’s in that compound???

Percent by mass (%) = mass of element x 100

mass of compound

Percent by Mass

What is the percentage of oxygen in water??

H2O

1. Find mass of each element on Periodic table

MassH = 1 g/mol

MassO = 16 g/mol

Percent by Mass

2. Find mass of total compound by adding up grams of each element in compound.

MassH = 1 g/mol

MassO = 16 g/mol

Mass of H2O = (2 x 1) + (1x16) = 18 g/mol

There’s 2 Hydrogens!MassH MassO

Percent Mass

3. Take the mass of molecule of interest (Oxygen in our case) and divide by the TOTAL mass found in step 2

% Oxygen = 16 g/mol x 100 = 88.9%

18 g/mol

Whats the % mass of Oxygen in CO?

1. Find mass of each element on Periodic table.

2. Find mass of total compound by adding up grams of each element in compound.

3. Take the mass of molecule of interest and divide by the TOTAL mass (found in step 2).

Warm – Up!

• Use the Matter chart to classify the following:

– Sugar water

– Sodium

– Sugar

– Raisin bread

• What is the relationship between mixtures and substances?

• What is another term for homogeneous mixtures?

Practice Problems• A 78 g sample of an unknown compound contains

12.4 g of hydrogen. What is the percent by mass of hydrogen?

• 1.0 g of hydrogen reacts completely with 19.0 g of fluorine. What is the percent by mass if hydrogen in the compound that is formed?

• If 3.5 g of element X reacts with 10.5 g of element Y to form the compound XY, what is the percent by mass of element X in the compound? Of Y?

• Two unknown compounds are tested. Compound 1 contains 15.0 g of hydrogen and 120.0 g of oxygen. Compound 2 contains 2.0 g of hydrogen and 32 g of oxygen. Are the compounds the same?? Explain.

Separating Mixtures

• Filtration – separates

solids from liquids

Separating Mixtures

• Distillation – separates

liquids by boiling point

Separating Mixtures

• Crystallization – removes pure solids from solutions by saturating the solutionand forcing the solid tocrystallize.

Separating Mixtures

• Sublimation – separates two

solids by transitioning from

the solid to vapor without

melting. The vapor then

undergoes deposition to form

pure crystals.

Separating Mixtures

• Chromatography – separates

liquids or gases by using a

mobile phase and a stationary

phase. Separation occurs as

one component sticks to the

stationary phase while the

other does not.

Law of Multiple ProportionsWhen elements combine to form compounds, different masses of one element combine with the same relative mass of the other element

in a ratio of small whole numbers.

H2O and H2O2 contain the SAME elements. Water is 2 parts H and 1 part O

Hydrogen Peroxide is 2 parts H and 2 parts O

If we compare the mass of O in both compounds we get 2:1

Practice Problem

Carbon reacts with oxygen to form two different compounds. Compound 1 contains 4.82 g of carbon for every 6.44 g of oxygen. Compound 2 contains 20.13 g or carbon for every 53.7 g of oxygen.

What is the ratio of carbon to a fixed mass of oxygen for the two compounds?

Compare the mass ratio.

Warm – Up!

• What is the percent mass of Cl in HCl?

• How many grams of salt and how many grams of water would you use to prepare 85 g of a solution that is 12.0% salt?

• A mineral has a copper content of 25.5%. In a certain experiment, 561 grams of copper were recovered from a pure sample of the mineral. What was the mass of the sample?

Agenda

• Warm Up!

• Pre-lab – MUST COME TO LAB COMPLETED

– Equipment

– Statement of Problem

– Relevant Background and Procedure

• Chapter 3 Worksheet

REMEMBER:

Aluminum Lab and HW probs – Due Wednesday

Test Corrections – Due Thursday

Warm – Up!

• H2O dissolves solid CuCl2 to form a blue liquid.

– Is this a physical or chemical change?

– Where would the product be categorized on the matter chart?

– CuCl2 burns green, is this a physical or chemical property?

– What is the percent Cl in CuCl2?

• Zn metal is added to the blue liquid to form a clear liquid of solid Cu and ZnCl2– Is this a physical or chemical change?

– What is the percent Cl in ZnCl2?