Water = 2 Hydrogen atoms + 1 Oxygen atom “H2O”

H-Bonds Continued: Water H-Bonds are why water molecules stick together so well to each other and other materials. Also… Pg 41

H-Bonds Continued: Water

Learning Objectives: Tell the connection between a solvent, solute and solution (Pre-AP only) Tell the connection between Hydroxide ions and hydrogen ions Tell what the connection between Acids, Bases and Water Know how to read the pH scale and it recognize its unique properties

Phases of matter: Chemistry in liquids Solid Liquid Gas all are important for life but which would you think is the most important? Liquid: cells are mostly water (H20) so that’s where most biological reactions (rxn) occur Chemistry in liquids Solution –liquid containing 2 or more chemical compounds solute solution Solvent –(in a solution) a chemical that can dissolve other compounds (usually liquid) Solute –(in a solution) a chemical that is dissolved (usually solid) solvent

What is the most important solvent for all living things? Water (DUH!) Also Remember that it has polar covalent bonds O H δ+ δ- O H δ- δ+ Water: “the Break-down” H+1 OH-1 + hydrogen ion hydroxide

+ H+ OH- H2O O H [H+] = concentration of hydrogen ions Water cont.. H+ hydrogen ion OH- + hydroxide ion H2O + No e- s left +1 O H -1 Acid: any compound that, when dissolved in water, increases [H+] Base: any compound that, when dissolved in water, increases [OH-] [H+] = concentration of hydrogen ions [OH-] = concentration of hydroxide ions

pH : measure of [H+] or [OH-] scale of 1  14 Acid  Base

More Acidic [H+] > [OH-] [H+] = [OH-] (Pure H2O) Neutral More Basic pH scale More Acidic [H+] > [OH-] [H+] = [OH-] (Pure H2O) Neutral More Basic [H+] < [OH-]

Power of the pH Scale: The pH scale is a logarithmic scale so the units are NOT equally spaced like you’d normally see 1000x More Acidic than pH = 6 pH = 3 pH = 6 pH = 5 pH = 4 pH = 3 pH = 2 pH = 1 10x more acidic Equal Spacing pH = 4 100x more acidic 10x more acidic pH = 6 pH = 5 10x more acidic

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