3polar molecules, ( 161)Molecules that have unequal distribution of charges, they have oppositely charges regions. This is due to the unequal sharing of the electrons In the polar covalent bonds It “shapes” the molecule!
47. Relate the shape of a water molecule to the distribution of electrons
55. Because of water’s chemical structure, the molecule is _polar___ allowing it to mix with and be a solvent to all things that are polar____. (Polar or non polar?)
6hydrogen bond 161A weak interaction involving a hydrogen atom and a fluorine, oxygen or nitrogen atom. It is a strong type of van der Waals force that holds water molecules together and gives water its special properties!Like holding hands the molecules are attracted to each other by their polarity!
7mixture, 163A combination of 2 or more substances in which each substance retains its individual characteristics and properties.Notes: New substances are not produced when a mixture is made, A solution is made. No chemical reaction takes place. A uniform mixture is called homogeneous.
8solvent,163In a solution the mixture in which the other substance is dissolved. Usually liquid.The tea is the solvent the sugar will be the solute
9solute, 163 The substance dissolved in the solvent. Sugar is a solute in sweet teaHeat usually makes it dissolve faster,
108. What are the two parts of a solution? Solvent and soluteIn a sugar solution, sugar is the solute? What is the water? The solvent
11SC.912.L.18.12Discuss the special properties of water that contribute to Earth's suitability as an environment for life: cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent. (MC AA)See page 162!
16Capillary ActionWater “pulls” itself up a tube by its adhesion to the sides of the tube
17pH activity item pH paper pH probe Make a data chart of the items to be testedTest the pH using the paper strips and the pH probe and record the numbers
18Water Labs!Write the answers to the following activities on your own paper!
19Penny activity Make a chart Drop water on the head side of a penny trialwaterWater with soap123averageMake a chartDrop water on the head side of a pennyCount the drops and record the number of drops that stay on the penny.Calculate the average of three trials.Add one drop of soap to the water and repeat the process.
20WHY 1. Why did the water form a dome on the penny? 2. What is the reason it stayed on the penny so long? Use the information you know about water molecules to answer this question.3. What happens to the number of water drops when soap is added to the water?Why?
21WET1. what do we call the water molecule because it has a positive side and a negative side?2. What does it mean for water to wet something?3. What type of molecules can get “wet” with water?4. What type of molecules can not be wet but instead repel water?
22chromatography1. Draw a thin line on the bottom of your filter paper with a permanent black marker.2. Do this on a second strip with a Vis a Vis marker.3. hold the strip in the water so that only the very tip end is getting wet.4. Allow the water to move up the paper strip.5. Observe what happens.
23S for sharpie V for Vis a Vis Thin line of the marker near the bottom
24Don’t let it touch the bottom or the sides of the container but let the water touch the bottom of the paper strip! Do not let the line go under the water!!!
25WHY? 1. Describe what happened to each of the strips. 2. Is the permanent marker soluble in water? Is it polar or non polar?3. Is the VIS a VIS soluble in water? Is it polar or non polar?4. What is true about the number of and types of pigments that make up the black marker?
26Now…Draw 2 water molecules and show the electrons and charges. Show how each molecule is formed by showing the chemical bonds within the molecule as well as between the two molecules.Using the diagram, explain why water has special characteristics that make it so important to living organisms.
27Diffusion Get two cups of water. Put several ice cubes in one cup. Drop food coloring into the cup and observe what happens.Make a hypothesis as to what would happen if the second cup of water if it were heated prior to the drops of coloring being added. Now try it.Explain why this happens.
29List the reasons why each property is important to life. See page 162 1. cohesive behavior: surface tension, droplets,2. ability to moderate temperature: maintains homeostasis, environments suitable for life,3. expansion upon freezing: mixes nutrients due to density differences, ice floats allowing fish to live under it,4. versatility as a solvent: universal solvent, polar substances dissolve in it allowing for transport of many substances into and out of many organisms
306. What is it about water’s chemical makeup that makes it have these properties? It is polar and has hydrogen bonds that make it stick together causing cohesion and adhesion. This also causes the highHeat of vaporization and solubilityFor polar substances
31acids, 164Substances that release hydrogen ions when they are dissolved in water. H+The more H+ the more acidicOn the pH scale these are low numbers0-6
32bases,164Substances that release hydroxide ions OH- ions when dissolved in water.Also called alkaline.Sodium hydroxide is an example. High numbers on the pH scale.8 -14
33pH, 165 The measure of the H+ ions in concentration is the pH Pure water has a pH of7 the H= equals the OH-Test strips like these can beused to determine the pH.Proper pH is needed forreactions to occur and enzymesto work
34Mixtures that can react with acids or bases and keep the pH within a particular range. The cell has buffers to keep the pH in the proper range for enzymes to function properly. Usually this is 6.5 to 7.5 but in the stomach this can be much more acidic and in the small intestine is can be more basic.buffers.165
35pH A measure of hydrogen ion concentration Scale 1- 14 1-6 acid 7 neutral8-14 base
379. Draw the pH scale. Label acid, base, and neutral 9. Draw the pH scale. Label acid, base, and neutral. Give an example of each.
38Water Lab 45 points Name ______________________________ pH activity: Measure the pH and put the numbers in the chart. 1 pt per number = 10 points
39ItempH paperpH probeWaterBleachMilk of magnesiaVinegarCitrus beverage
40Penny activity : record the number of drops on the head side and average 3 trials = 8 points waterWater with soap123average
41WHY? 4 points1. Why did the water form a dome on the penny? _______________________________________________________________________________________________________________________________________2. What is the reason it stayed on the penny so long? Use the information you know about water molecules to answer this question. ____________________________________________________________________3. What happens to the number of water drops when soap is added to the water? ______________________ Why? ________________________________________________________________________________________
42Wet 4 points1. What do we call the water molecule because it has a positive side and a negative side? ________________2. What does it mean for water to wet something? ______________________________________________________________________________________________________________________________________________3. What type of molecules can get “wet” with water?_________________________________________________4. What type of molecules cannot be wet but instead repel water? _____________________________________
43Chromatography 8 pts1. Describe what happened to each of the strips. 2ptsvis a vis: ______________________________________________________________________________________sharpie: ______________________________________________________________________________________2. Is the permanent marker soluble in water? ___________________Is it polar or non polar? _____________ 2 pts3. Is the VIS a VIS soluble in water? _____________ Is it polar or non polar? _________________________ 2 pts4. What is true about the number of and types of pigments that make up the black marker? 2 pts ________________________________________________________________________________________________________
44Draw 2 water molecules and show the electrons and charges Draw 2 water molecules and show the electrons and charges. Show how each molecule is formed by showing the chemical bonds within the molecule as well as between the two molecules. 6 pointsUse the circles to get your diagrams started. Add the dots for electrons and add additional circles to show how the water molecules will arrange themselves. Make sure to label the positive and negative sections!
45Using the diagram, Explain why water has special characteristics that make it so important to living organisms.5 points