Unit 1: Water: Exploring Solutions Miss Shuey ChemComm
Essential Questions • What techniques can we use to purify water? • What are the physical properties of water? • Why do some substances readily dissolve in water and others do not? • How does chemistry contribute to effective water treatment?
Article review • Fish Kill Triggers Riverwood Water Emergency
Section A: Sources and uses of water • Uses of water: • _________________________ • _________________________ • _________________________ • _________________________ • _________________________ • _________________________ • _________________________ • _________________________ • _________________________ • _________________________
A.4 water supply and demand • Family of four uses 390 gallons daily. • Direct water use – volume that can be directly measured. • Indirect water use – hidden uses of water that you may never have considered. • Ex. Slice of pizza?? Figure 1.12
A5. water use in the us • For each region in the US, name the greatest single use of water. • A. the east b. the south c. the midwest • D. the west e. alaska f. hawaii Explain the differences in how water is used in the east and the west. Think about where most people live and where most of the nation’s factories and farms are located. What other regional factors help explain the general patterns of water use? List two factors about the weather, economy, or culture that could explain the greatest water use within each of these six U.S. regions.
a.6 where is the world’s water? • 97% of the world’s water. • Ocean • Glaciers
Physical states of water • Gaseous state: water vapor • Liquid state: lakes, rivers, oceans, clouds, and rain. • Solid state: ice
City water • Surface water: water supply originated in a river or other body of water. • Ground water: water in a well.
Rural water • Aquifer: water-bearing layer of rock, sand, or gravel, then pumped to the surface.
A.8 RIVERWOOD WATER USE • Pg.22 • http://www.youtube.com/watch?v=xxNfJLMNS4E&list=FLHywkjQDas46hk_l2QAeKaA&feature=mh_lolz
Scientific Method Hypothesis – testable statement controls – remain constant variable – is changed Model – explanation of how phenomena occur and how data or events are related. Theory – broad generalization that explains a body of facts or phenomena.
Accuracy and Precision • Accuracy – close to the expected value • Precision – a number of measurements close to each other.
What is more accurate? Graduated cylinder Or Beaker
Significant Figures • Indicates how precise a measurement is.
Sig fig practice Perform these calculations following the rules for sig figs. • 26 x 0.02584 = ? • 15.3 / 1.1 = ? • 782.45 - 3.5328 = ? • 63.258 + 734.2 = ?
SI unit – measurements in science. Volume Density – m/v A sample of aluminum metal has a mass of 8.4g. The volume of the sample is 3.1 cm3. calculate the density of aluminum.
Dimensional analysis – math technique that allows you to use units to solve problems involving measurements.
Section b • Article reading • B.1 PHYSICAL PROPERTIES OF WATER • Matter – anything that occupies space and has mass. • Physical properties: observed and measured without changing the substance. • Density – mass of material within a given volume. • D = m/v
Water properties • Freezing point – 0 C when liquid water forms a solid. • Aqueous solution – water-based solution. • Important aqueous solutions in your life: • ____________________ • ____________________ • ____________________
b.3 mixtures and solutions • Mixture – when two or more substances combine and retain their individual properties. • Heterogeneous (suspension) • Homogeneous (solution) • Solute • Solvent • Pg.30
b.4 Particulate view of water • Particulate level – at the level of its atoms and molecules. • Atoms – building blocks of matter. • Element – matter made up of only one type of atom. • Compound – composed of the atoms of two or more elements bonded together in fixed proportions. • Ex.
Chemical formulas – representing compounds or elements, showing ratios of how they bond. • Ex. • Substance – element or compound with uniform and definite compositions. • Molecule – smallest unit of a molecular compound that retains the properties of that substance.
b.5 pictures in the mind • Macroscopic – large-scale, easily observed without microscopes or other tools. • Models – representations of atoms and molecules. • Pg.33 ques. 1-7
b.6 symbols, formulas, and equations • Chemical symbols – letters to represent element. • Periodic table of the elements – arrangement of elements according to the number of protons.
Common elements Aluminum Al Hydrogen H Bromine Br Iodine I CalciumCaIron Fe Carbon C LeadPb ChlorineClMagnesium Mg Cobalt Co Mercury Hg Copper Cu Nickel Ni Fluorine F Nitrogen N Gold Au Oxygen O Phosphorus P Potassium K Silver Ag Sodium Na Sulfur S TinSn
What element is this? K potassium
What element is this? Al aluminum
What element is this? Br bromine
What element is this? Ca calcium
What element is this? C carbon
What element is this? Cl Chlorine
What element is this? Co Cobalt
What element is this? F Fluorine
What element is this? Au Gold
What element is this? H Hydrogen
What element is this? I Iodine
What element is this? Fe Iron
What element is this? Pb Lead
What element is this? Mg Magnesium
What element is this? Hg Mercury
What element is this? Ni Nickel
What element is this? N Nitrogen
What element is this? O Oxygen
What element is this? P Phosphorus
What element is this? Ag Silver
What element is this? Na Sodium