objective 4: structures and properties of matter

Objective 4:Objective 4: Structures and Properties Structures and Properties

of Matterof Matter

IPC 7A – Investigate and IPC 7A – Investigate and identify properties of fluids identify properties of fluids including density, viscosity including density, viscosity

and buoyancy.and buoyancy.

DensityDensity

Density = mass volume

D = M V

Math Tip for DensityMath Tip for Density

D =

M V 1

Cross Multiply

BuoyancyBuoyancy

The force that acts on objects immersed in or The force that acts on objects immersed in or floating on a liquidfloating on a liquid

Photo from: http://www.seed.slb.com/en/scictr/watch/bathroom/duck.htm

BuoyancyBuoyancy

Buoyancy is related to floatingBuoyancy is related to floating an object in a liquid is buoyed up (pushed up) by a an object in a liquid is buoyed up (pushed up) by a

force equal to the weight of the liquid the object force equal to the weight of the liquid the object displaces (pushes aside). This is known as displaces (pushes aside). This is known as Archimedes’ Principle. Archimedes’ Principle.

Photo from: http://www.seed.slb.com/en/scictr/watch/bathroom/duck.htm

ViscosityViscosity

Viscosity is the resistance of a liquid to flowViscosity is the resistance of a liquid to flow

If a liquid flows slow, it is viscous, or has a If a liquid flows slow, it is viscous, or has a high viscosityhigh viscosity

The Great Salt Lake

The Great Salt Lake is a large inland lake. It is very unusual because it is made up of saltwater. In 1959 a railroad causeway was built across the lake. The causeway, made from rocks and cement, divides the lake into two bays, Gilbert Bay and Gunnison Bay. Although the material in the causeway is tightly packed, the causeway is porous, allowing for the exchange of water between the two bays. Over time, as fresh surface water flows into the Great Salt Lake, the depth of each bay and the composition of the water can vary. More freshwater flows into Gilbert Bay than into Gunnison Bay. Therefore, the water in Gunnison Bay is saltier than the water in Gilbert Bay. When the difference in salt composition is great, some of the saltier water from Gunnison Bay flows into Gilbert Bay through the causeway. Some properties of both bays were measured in 1998 and are shown in the table below.

From the data in the table, what would be the mass of a 3.0 L sample of water collected from Gunnison Bay?

A 2515 g

B 3171 g

C 3579 g

D 4193 g

What is the density at 20°C of 12.0 What is the density at 20°C of 12.0 milliliters of a liquid that has a mass of milliliters of a liquid that has a mass of 4.05 grams? 4.05 grams?

AA 0.338 g/mL 0.338 g/mL

B B 2.96 g/mL2.96 g/mL

C C 16.1 g/mL16.1 g/mL

D D 48.6 g/mL48.6 g/mL

Powerful PlanktonPowerful PlanktonThe U.S. Naval Research Laboratory has created an experimental The U.S. Naval Research Laboratory has created an experimental marine fuel cell that could produce enough electricity to power marine fuel cell that could produce enough electricity to power ocean-monitoring devices. This fuel cell runs on seawater and ocean-monitoring devices. This fuel cell runs on seawater and sediment, with the help of plankton. Some plankton on the surface sediment, with the help of plankton. Some plankton on the surface of ocean sediments use dissolved oxygen to break down organic of ocean sediments use dissolved oxygen to break down organic matter, releasing energy; this is an aerobic process. The plankton in matter, releasing energy; this is an aerobic process. The plankton in the deeper sediments break down organic matter without using the deeper sediments break down organic matter without using oxygen; this is an anaerobic process. These two processes create a oxygen; this is an anaerobic process. These two processes create a difference in voltage between the surface of the sediment and the difference in voltage between the surface of the sediment and the sediment farther down in the seabed. The voltage difference can be sediment farther down in the seabed. The voltage difference can be used to produce electricity-up to 5.0 x 10 – 2 watts of power. Energy used to produce electricity-up to 5.0 x 10 – 2 watts of power. Energy supplied by this type of fuel cell can be obtained as long as there is supplied by this type of fuel cell can be obtained as long as there is organic matter in the sediment.organic matter in the sediment.

What is the mass of a 500.00 mL sample of seawater with a density What is the mass of a 500.00 mL sample of seawater with a density of 1.025 g/mL? of 1.025 g/mL?

F F 487.8 g487.8 gG G 500.0 g500.0 gHH 512.5 g 512.5 gJ J 625.0 g625.0 g

Which of the following objects will float on water?

IPC 7E – Classify samples IPC 7E – Classify samples of matter from everyday life of matter from everyday life

as being elements, as being elements, compounds, or mixtures.compounds, or mixtures.

2 Classes of Matter

MixturesPure Substances

Pure Substances

ElementsCompounds

MIXTUREmatter that contains 2 or more materials

that can be physically

separated (ex. cheeseburger &

Lucky Charms)

2 TYPES OF MIXTURES

• Heterogeneous• Homogeneous

mixture made up of TWO

OR MORE distinct phases

with different properties (not uniform throughout)

Heterogeneous Mixture

Examples: salad, vegetable soup,

concrete

SUSPENSION

contains a liquid in which visible particles settle

scatter lightcan be separated using filter

paperEx: Italian salad dressing

COLLOIDparticles are mixed together, but not dissolved; scatter

light; will not separate upon standing; appear

cloudy; ex: shaving cream

Homogeneous Mixture

mixture made up of ONLY 1 phase

(uniform throughout)

Examples of Homogeneous Mixtures

Also: Salt Water, Sugar Water and most clean air

!Homogeneous Mixtures are

also known as SOLUTIONS!

Solutions are made

up of two parts• Solute• Solvent

SOLUTEthe part of a

solution that is dissolved

SOLVENTthe part of a

solution that does

the dissolving

SOLUTION!!!

=

Solvent

Solute

Solubilityamount of solute that will dissolve in an amount of

solvent at a given temperature

Saturated Solution contains the

maximum amount of solute for an

amount of solvent at a given

temperature

Unsaturated Solutioncontains less solute

than a saturated solution

Supersaturated Solution

contains more solute than it

should theoretically be able to hold at a

certain temp

Salt is added to a beaker of water and stirred until it is completely dissolved. The salt in this mixture can be separated by —

A chromatography

B chemical means only

C passing the water through filter paper

D allowing the water to evaporate slowly

The picture shows a model of the element —

A fluorine

B helium

C beryllium

D oxygen

The first equation represents photosynthesis. Plants use The first equation represents photosynthesis. Plants use energy from sunlight to produce sugar and oxygen from energy from sunlight to produce sugar and oxygen from carbon dioxide and water. The second equation carbon dioxide and water. The second equation represents aerobic respiration. Plants and animals represents aerobic respiration. Plants and animals release stored energy in a reaction between sugar release stored energy in a reaction between sugar molecules and oxygen. This reaction produces carbon molecules and oxygen. This reaction produces carbon dioxide and water.dioxide and water.

Oxygen (OOxygen (O22) is an example of —) is an example of —A A an alloyan alloyBB a molecule a moleculeC C a salta saltD D a mixturea mixture

An unknown silvery powder has a constant An unknown silvery powder has a constant melting point and does not chemically or melting point and does not chemically or physically separate into other substances. The physically separate into other substances. The unknown substance can be classified as —unknown substance can be classified as —

AA an element an element

B B a compounda compound

C C a mixturea mixture

D D an alloyan alloy

IPC 8A – Distinguish between physical and

chemical changes in matter such as oxidation,

digestion, changes in state, and stages of the rock

cycle.

Physical ChangesPhysical Changes

More ExamplesMore ExamplesCuttingCuttingBreaking apartBreaking apart

All of these represent a change in state ofmatter except —

A melting an ice block

B evaporating alcohol

C sublimating dry ice

D digesting a sugar cube

In the rock cycle, which of these is a chemical change involved with the formation of igneous rocks?

F Compression of sediments

G Heat loss from lava

H Subduction of plates

J Formation of minerals

Which of the following is an example of a chemical change?

F Ice cracking

G Sugar dissolving

H Milk souring

J Lead melting

What characteristic of water remains the same no matter what is dissolved in it ?

A The ratio of hydrogen to oxygen

B The ability to refract light

C The hydroxide ion concentration

D The freezing temperature

Which of these describes a pollution-producing Which of these describes a pollution-producing process that involves only a physical change? process that involves only a physical change?

A A Coal with a high sulfur content is burned, Coal with a high sulfur content is burned, producing gases that cause acid rain.producing gases that cause acid rain.

B B Chlorofluorocarbons are released, changing Chlorofluorocarbons are released, changing ozone in the upper atmosphere into oxygen.ozone in the upper atmosphere into oxygen.

CC Hot wastewater is discharged into a lake, Hot wastewater is discharged into a lake, lowering oxygen levels in the water.lowering oxygen levels in the water.

D D Nitrogen oxide emissions combine with water Nitrogen oxide emissions combine with water vapor, producing nitric acid.vapor, producing nitric acid.

IPC 8C – Investigate and IPC 8C – Investigate and identify the law of identify the law of

conservation of mass.conservation of mass.

Law of Conservation of Mass

Mass can not be created or Mass can not be created or destroyeddestroyed

Using the Law of Conservation of Using the Law of Conservation of massmass

2H2H22 + O + O22 2H 2H22OO

HH22O(s) O(s) H H22O(l)O(l)

C + OC + O22 CO CO22

100 grams 50 grams ?150 grams

32 grams 32 grams

60 grams20 grams ?40 grams

Balancing EquationsBalancing Equations

A reaction must be balanced to A reaction must be balanced to obey the law of conservation obey the law of conservation

of massof mass

Non-balanced ReactionNon-balanced Reaction

HH22 + O + O22 H H22OO

Balanced ReactionBalanced Reaction

2H2H22 + O + O22 2H 2H22OO

How to balance a reaction How to balance a reaction

Step one: list all the element symbols Step one: list all the element symbols under the arrow of a reactionunder the arrow of a reaction

HH22 + O + O22 H H22OO

HO

How to balance a reactionHow to balance a reaction

Step two: count how many of each atom Step two: count how many of each atom you have on each side of the reactionyou have on each side of the reaction

HH22 + O + O22 H H22OO

HO

2 22 1

CoefficientsCoefficients

Numbers that are placed in Numbers that are placed in frontfront of a of a compound/molecules in a reactioncompound/molecules in a reaction

How to balance a reactionHow to balance a reaction

Step three: add coefficients to the Step three: add coefficients to the compounds to help make each element compounds to help make each element even on both sideseven on both sides

HH22 + O + O22 H H22OO

HO

2 22 1

42

422

The reactionThe reaction

HH22 + O + O22 H H22OO22

2 1

Balance Me!Balance Me!

___ XeF___ XeF22 + ___ H + ___ H22O O __ Xe + __ O __ Xe + __ O22 + __ HF + __ HF

XeF

1 12 14

2

2

24 H

O1 2

2

2

22

22

4

4

4

If 43.7 g of iron is completely used in the reaction above, how many grams of oxygen are involved in the reaction? Record and bubble in your answer to the nearest tenth on the answer document.

18.8g

The first equation represents photosynthesis. Plants use energy from sunlight to produce sugar and oxygen from carbon dioxide and water. The second equation represents aerobic respiration. Plants and animals release stored energy in a reaction between sugar molecules and oxygen. This reaction produces carbon dioxide and water.

To produce 4 molecules of sugar, a plant needs —

F 6 molecules of hydrogenG 12 molecules of ATPH 18 molecules of waterJ 24 molecules of carbon dioxide

What are the coefficients that will balance What are the coefficients that will balance this chemical equation? this chemical equation?

A A 2, 1, 12, 1, 1

B B 3, 4, 23, 4, 2

CC 2, 2, 1 2, 2, 1

D D 4, 3, 2 4, 3, 2

The illustrations show a conservation-of-mass experiment. The solution in the beaker lost mass because —

F materials have less mass at high temperatures

G the mass of the reactants and products was less than 100g

H sodium sulfate (Na2SO4) is lighter than air

J some of the water molecules turned into gas

IPC 9A – Relate the structure of water to its

function [as the universal solvent].

The water molecule: formula

2. How many types of atoms in a water molecule?

1. What is the chemical formula for water? H2O

2 (hydrogen and oxygen)

3. What is the total number of atoms in a water molecule?

3 (2 hydrogen and 1 oxygen)

The Water Molecule: Polarity

1. Polar refers to unequal sharing of electrons.Polarity creates partial positive charges and partial negative charges.

Look at your periodic table: 2. How many protons does an oxygen atom have

in its nucleus?

3. How many protons does a hydrogen atom have in its nucleus?

The charge of the nucleus of an oxygen atom is +8.

8

The charge of the nucleus of a hydrogen atom is +1.

1

In a water molecule, are the electrons more likely to be near the oxygen nucleus or the hydrogen nucleus?

Oxygen nucleus

Hydrogen bondingHydrogen bonding

H

H

HH

H

H

HH

H HH H

O

O

O

O

OO

(-)

(-)

(-)

(-)

(-)

(-)

(+)(+)

(+)

(+)

(+)

(+)

(+)

(+)

(+)(+)(+)

(+)

Why are the charges in parentheses? they are partial charges

Which factor makes water an effective solvent? Which factor makes water an effective solvent?

F F The presence of molecular oxygenThe presence of molecular oxygen

G G Its lack of covalent bondsIts lack of covalent bonds

HH The polar nature of its molecules The polar nature of its molecules

J J Its abundance on Earth’s surfaceIts abundance on Earth’s surface

IPC 9D – Demonstrate how various factors influence

solubility including temperature, pressure, and

nature of the solute and solvent.

More solute will result in a boiling point More solute will result in a boiling point elevation (increase) and freezing point elevation (increase) and freezing point depression (decrease)depression (decrease)

Why do people put salt on icy roads?Why do people put salt on icy roads?

The Great Salt Lake

The Great Salt Lake is a large inland lake. It is very unusual because it is made up of saltwater. In 1959 a railroad causeway was built across the lake. The causeway, made from rocks and cement, divides the lake into two bays, Gilbert Bay and Gunnison Bay. Although the material in the causeway is tightly packed, the causeway is porous, allowing for the exchange of water between the two bays. Over time, as fresh surface water flows into the Great Salt Lake, the depth of each bay and the composition of the water can vary. More freshwater flows into Gilbert Bay than into Gunnison Bay. Therefore, the water in Gunnison Bay is saltier than the water in Gilbert Bay. When the difference in salt composition is great, some of the saltier water from Gunnison Bay flows into Gilbert Bay through the causeway. Some properties of both bays were measured in 1998 and are shown in the table below.

After studying salinity in the bays of the Great Salt Lake, students prepared two samples of water having different salinity. Sample A contained 10% salt, and Sample B contained 25% salt. Both samples were the same size. After leaving the samples in the freezer for the same amount of time, the students discovered that a layer of ice had formed in each sample. Which layer in the samples probably contained the most salt?

A The ice layer in Sample A

B The liquid layer in Sample A

C The ice layer in Sample B

D The liquid layer in Sample B

Which of the following salts has the greatest solubility in water at 25°C?

F CaCO3

G FeSH HgCl2J KClO4

As a scuba diver goes deeper underwater, As a scuba diver goes deeper underwater, the diver must be aware that the increased the diver must be aware that the increased pressure affects the human body by pressure affects the human body by increasing the —increasing the —

A A body’s temperaturebody’s temperatureBB amount of dissolved gases in the body amount of dissolved gases in the bodyC C amount of suspended solids in the bodyamount of suspended solids in the bodyD D concentration of minerals in the body concentration of minerals in the body