Monday Nov 17 th -Week 15 TOPIC : Water and Solutions  OBJ : 9-11 DO NOW : EXT : DUE DATE : DW: Solute Worksheet EXIT : Fill in your level of understanding DISTINGUISH between solutions and suspensions. HANDOUTS to PICK-UP: -6.3 Notes -6.3 Solute/Solvent Handout SEMINAR 2: -Quiz for 6.1 & 6.2 BEFORE/AFTER SCHOOL:  DW-None -Objectives Check -Binder Organization -6.3 Notes -Worksheet Draw a water molecule. Show all bonds using Bohr Models AGENDA ABSENT Science of Life

Monday: ___11__/__17___ OBJECTIVE…  #_9-11_____ TOPIC: Water and Solutions Daily Work Grade- None DW GRADE:  2  1  0 Monday DO NOW Q: Draw a water molecule. Show all bonds using Bohr Models A:

Today’s Objectives 9-   -- IDENTIFY how the properties of water make it well suited to help maintain homeostasis in an organism 10-   --DETERMINE pH of various substances and DESCRIBE the use of the pH scale 11-   --COMPARE / CONTRAST acids and bases and DESCRIBE how buffers affect cells.

Vocabulary These should be done by test day!  -polar molecule / nonpolar molecule  -hydrogen bond  -acid / base  -pH / buffer  -adhesion / cohesion H

6.3 WATER & SOLUTIONS  WHAT YOU WILL LEARN -about properties of water -water’s polarity -how acids differ from bases  rev- homeostasis  MAIN IDEA: Properties of water help organisms maintain homeostasis

-water vital to life on earth -properties -provide environments suitable for life -help maintain homeostasis -book pic P162 -UNIVERSAL SOLVENT: separate the ions -many substances dissolve in water -ADHESIVE: attraction with other surfaces -COHESIVE: attracted to each other [hold liquid together] -POLAR: slight (+) / slight (-)  Visualizing Properties of Water  WATER’s PROPERTIES HUMANS- -survive days w/o food -only few days w/o water

POLARITY: -property of having 2 OPPOSITE poles/ends  IDENTIFY type of bond:_______________ /how many bonds:_____  WATER’s POLARITY DRAW a lewis structure of 2 HYDROGEN and OXYGEN atoms O H COVALENT 2 NONPOLAR- equal distribution e- among atoms A R R

 WATER’s POLARITY 1-__________________________ 2-__________________________ 3-__________________________ 4-__________________________  How many water molecules shown?______ HYDROGEN BOND: -weak interaction involving H ( flourine, oxygen, nitrogen) O: negative end (-) H: positive end (+) hydrogen bond covalent bond 5

REASONS - electrons more strongly attracted to O nucleus than H nucleus -causes bent shape EFFECTS -form bonds with other polar molecules -readily form solutions  WATER’s POLARITY/ reasons/effects

What is a mixture? -A combination of 2 or more substances -Each retains individual characteristics or properties ex: tossed salad, mixed bag of M&Ms, Salt Water 2 Different Types: Homogenous-uniform composition throughout ex: crystal light Heterogenous-components remain distinct ex: Salad  MIXTURES w/ WATER solution

SOLUTION- -another name for HOMOgenous mixture SOLVENT- -SUBSTANCE in which ANOTHER is DISSOLVED SOLUTE- -SUBSTANCE that IS DISSOLVED  IDENTIFY the property of water that makes it a good SOLVENT- -POLARITY  MIXTURES w/ WATER solution

DEMO

ACIDS -  increase in hydrogen ions -a solution that has an excess of H + ions HYDROGEN IONS- -positively charged ion of hydrogen H + BASES -  decrease in hydrogen ions -a solutions that has an excess of OH - ions HYDROXYL IONS- -negatively charged ion of hydroxide OH -  ACIDS/BASES/pH

 Acids & Bases Examples

 ACIDS/BASES/pH WATER release MANY H + release FEW H + release FEW OH - release MANY OH -

pH- “power of the hydrogen ion” -ion: charged atom or molecule IDENTIFY what the pH scale measures- -how acidic / basic substance is -substances INCREASE / DECREASE # H + ACIDICNEUTRALBASIC  ACIDS/BASES/pH

 pH Play this game!

-solution which RESIST changes in pH when small quantities of an acid or alkali added to it. -keep pH "in range": Organisms SURVIVE and FUNCTION despite metabolic activities that shift pH (acid/basic end of scale)  DISCUSS/IDENTIFY the importance of buffers in biology. -bring organism back to balance  HOMEOSTASIS  BUFFERS

1- IDENTIFY the independent variable. -pH/temp 2- IDENTIFY the dependent variable. -protease activity 3- IDENTIFY the range of pH values used in the experiment. -pH range IDENTIFY the range of temperatures used in the experiment. -temp range 30-90C  DATA ANALYSIS

5- SUMMARIZE the results of the two graphs. -highest activity pH10 / 60C 6- INFER/SUPPORT- if laundry detergent is basic and requires hot water to be most effective, would this protease be useful? Yes, because the enzyme had the highest activity at a high pH (basic) and at a high temp.  DATA ANALYSIS

EXIT FILL-IN: level of understanding of today’s objective   EXIT: Describe a chemical reaction (in detail) that happens everyday!