what measures mass and the space something occupies? what

September 30, 2014

What measures mass and the space something occupies?

What measurement describes the mass per unit volume of things?

Matter

• Matter is the "stuff" everything is made of. Matter has two characteristics:> Matter has mass> Matter occupies space

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Density

• Density: the mass per unit volume of a substance.

Units: g/cm3 or g/mL

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Example 1: Calculating Density

• The volume of a piece of unknown metal is 88.1 ml. The mass of the metal is 1699.450 g. What is the density of the metal?> Can you identify the metal?

Copyright © 2000 Mary Hebrank, Duke Center for Inquiry-Based Learning, Duke University

• A chunk of Aluminum has a mass of 512 kg. What is the volume of the metal?

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1 Which of the following is the correct formula for density?

A D=V/m

B D=V*m

C D=m/V

D D=1/m

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Classifying Matter

• Matter can be classified in different ways:> States of matter> Composition

• What are the three (main) states of matter?

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States of Matter

• The three (main) states of matter are> Solid> Liquid> Gas

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States of Matter

Solid Liquid Gas

Shape

Volume

Particle

Movement

Definite shape

Indefinite shape: Shape of container

Indefinite shape: Shape of container

Definite volume

Definite volume

Indefinite volume: volume of container

Fixed, vibrate in place

Slide past one another

Move freely at high speeds

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2 If a substance has a definite volume but takes the shape of its container, it is best classified as a

A solid

B liquid

C gas

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3 In a _______, the particles move freely.

A solid

B liquid

C gas

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Density of a Solid, Liquid, and Gas

• How would you expect the densities of a solid, liquid, and gas to compare?

• *Will explore in a lab (Lab #2!)

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Classifying Matter by Composition

HeterogeneousHomegeneous

CompoundElement

Matter

MixturePure substance

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Has variable composition

Example: Soda, steel, air

Always has the same composition.

Example: Pure water, aluminum, table salt.

Pure Substance and Mixture

• A mixture is a type of matter that is made up of more than one kind of particle. It contains two or more pure substances.

• A pure substance is a type of matter that is made up of only one kind of particle.

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Pure substances can either be compounds or elements.

• Elements: pure substances that are only made up of one type of atom.> Cannot be broken down into other substances by

chemical means.> Example: Oxygen (O2), aluminum (Al)

• Compounds: pure substances that are made up of two or more types of atoms chemically bonded together.> Always have the same composition. > Example: Water is a compound. H2O. Water always

has 2 hydrogen atoms with 1 oxygen atom.

Br C OO Cl C

H H

H

H

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A mixture can be homogeneous or heterogeneous

• Homogeneous mixture: mixture is the same throughout.> Also called a solution> Example: Dissolve salt in water.

• Heterogeneous mixture: mixture is not uniform throughout. Different regions have different properties.> Example: Sand in water. Some regions contain

more sand.

http://www.askpins.com/pics/12/is-h2o2-homogeneous-or-heterogeneous.jpg

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4 A glass of sugar water is best described as a

A Pure substance

B Mixture

C Element

D Compound

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5 Compounds are an example of a ______ and have ___________

A mixture, variable composition

B pure substance, variable composition

C mixture, same composition

D pure substance, same composition

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Au

C

Li

H2O

CO2

NH3

granite

ocean water

soil

sugar water

air

wine

physical separation

chemical reaction

Classifying Matter by Composition

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Physical and Chemical Properties and Changes

• Physical property: can be observed or measured without changing the chemical nature of the matter.> Extensive property: depends upon the amount of

substance present.– Examples: Volume, mass, length

> Intensive: independent of the amount of substance present.

– Examples: Boiling point, density.• Chemical property: ability of a substance to combine

with or change into other substances.> Example: Combustion of butane

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Physical and Chemical Properties and Changes

• Physical change: a change in one or more physical properties. Does not change the composition of the substance. > Does not create a new substance.> Examples: Boiling water, mixing sand and water,

tearing a piece of aluminum foil.• Chemical change: a change in the composition of the

substance. A chemical change changes the substance into a different substance or substances.> Examples: Burning sugar to create CO2 and H2O

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physical separation

chemical reaction

Classifying Matter by Composition

• You need a chemical reaction to turn a compound into an element, and vice versa. (chemical change)

• You can physically separate mixtures. (physical change)

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Filtration

• Separate out heterogeneous mixtures• Based on particle size

http://en.wikipedia.org/wiki/Filtration

http://www.konia.com.au/technology_water_filtration.php

http://en.wikipedia.org/wiki/Coffee_preparation#mediaviewer/File:Manual_coffee_preperation.jpg

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Distillation

• Separation of homogeneous mixtures • Based on boiling point

> The substance with the lower boiling point vaporizes (boils and turns into gas) first, then can be condensed (turned back into liquid) and collected.

http://www.ssc.education.ed.ac.uk/bsl/chemistry/distillatione.html

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Chromatography

• Separation of homogeneous mixtures• Based on attraction of molecules in the mixture to

either the mobile phase or stationary phase.

http://www.micromountain.com/sci_diagrams/sci_app/sci_app_pages/ctography_lab_eng.htm

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6 Which of the following separates a mixture by size of particle?

A Filtration

B Distillation

C Chromatography

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7 Which of the following separates a mixture based on boiling point?

A Filtration

B Distillation

C Chromatography

September 30, 2014