1. Daily TAKS Connection: Water as the Universal Solvent IPC(9): The student knows how solution chemistry is a part of everyday life. The student is expected to: (A) relate the structure of water to its function [as the universal solvent].

2. Day 1 Construct a two tab foldable Materials: Foldable handout Scissors Pen Colored pencils/crayons Instructions: Hamburger fold the paper along the solid fold line Cut the paper along the center dashed line Record your name, date and period on the reverse Color the front of the foldable

3. Day 2 notes Record the following notes under the flap labeled “Water is the Universal Solvent” – Water is a “polar” molecule Slightly negative at the oxygen atom Slightly positive at the hydrogen atoms Like dissolves like Polar molecules dissolve polar molecules Most substances in nature are polar; therefore water dissolves most substances

4. Question Which factor makes water an effective solvent? a. The presence of molecular oxygen b. Its lack of covalent bonds c. The polar nature of its molecules d. Its abundance on Earth’s surface

5. Question The structure of pure water makes it a good — a.solvent b.catalyst c.conductor d.nutrient

6. Question Which characteristic of water best explains its ability to dissolve a great variety of materials? a.Its transparency in light b.Its electrical conductivity c.Its physical state of matter d.Its molecular arrangement

7. Question The graph shows the concentration of ions found in the water of the Dead Sea. Which property of water is responsible for the dissociation of salts that produces the ion concentrations shown in the graph? a.Chemical stability b.High polarity c.Low melting point d.High freezing point

8. Question The diagram above shows water molecules and ions from an NaCl crystal. What is the most likely reason that each water molecule is arranged so that the oxygen part of the molecule faces a sodium ion? a.The oxygen in a water molecule contains a partial negative charge. b.Gravity rotates the oxygen atoms to face the more-massive sodium ions. c.Hydrogen atoms create repulsive forces with chloride ions. d.Oxygen atoms form covalent bonds with sodium ions.

9. Day 3 notes Record the following notes under the flap labeled “Properties of Water that Never Change” – Water always contains two hydrogen atoms bonded to one oxygen atom 2:1 ratio Formula: H 2 0 Water expands when frozen Becomes less dense Ice floats!! Very important to aquatic life!!

10. Question If the properties of water were to change so that the solid form was denser than the liquid form, organisms living in a cold pond environment would be less likely to survive because water would no longer — a.dissolve enough oxygen from the air b.produce solutions containing vital nutrients c.remain neutral, instead becoming highly acidic d.produce a floating insulating layer of ice

11. Question Fish survive through severe winters because of the property of water that allows water to — a.form chemical bonds as it freezes, raising the water temperature below the ice b.increase in density while it freezes, dissolving more oxygen from the air c.expand when it freezes, creating a floating and insulating layer of ice d. precipitate vital nutrients when it freezes, increasing the food supply