Water
Core Objectives
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The importance of water for life, how its distributed in the Universe/Earth, the water cycle and how humans impact it
Water’s chemical formula, chemical structure & bonds, overall charge, and charge distribution within the molecule (polarity)
How the difference between the high electronegativity of oxygen and that of hydrogen cause water’s high polarity
How water’s high polarity contribute to each of its amazing properties
How hydrogen bonds form between water molecules and how they help give water’s amazing properties
5 Amazing Properties of Water (what they are, how each is caused by polarity/hydrogen bonds, and different ways through
which each helps life) = Less Dense as a Solid, High Specific Heat, High Heat of Vaporization, Adhesion, & Cohesion
How water potential, adhesion, and cohesion work together to cause capillary action and how that helps life
How the adhesive properties of water make it an excellent solvent that helps life in a variety of ways
How aqueous solutions occur when a water (solvent) dissociates (separates) ionic compounds and/or surround polar areas of covalent
compounds to dissolve these solutes
How polar molecules and nonpolar molecules interact in mixtures
Compare acids and bases in terms of ions added to water, taste, texture, reaction to indicators, pH range, and examples
The impact of acids and bases in biological systems (denaturing, acid rain, digestion, acidosis)
Biological buffers help prevent massive pH changes
Key Terms
Water – The Molecule of Life
Compound of Life
Universal Solvent
Space Biology
Evidence of Evolution (Shared characteristic = homology)
Origin of Life
Importance of Water
Water Distribution & Use
Water in the Universe
% Salt Water vs. % Fresh Water
Fresh Water Sources
Water Uses (Irrigation, Household, Industrial, Electricity)
Water Scarcity
Water Cycle
Evaporation
Transpiration
Condensation
Precipitation
Runoff
Water Chemistry
Chemistry Review
Atoms (Nucleus, Electron Cloud)
Electron Configuration & Balance
Electronegativity
Water
Chemical formula
Shape
Polarity
Net Charge
Net Charge vs. Polarity (Charge distribution)
Hydrogen Bonds
Weak van deer Waals
H vs. Electronegative atoms (F,O,N) from adjacent molecules
Water hydrogen bonds structure
Strength in numbers
Magnetic properties
Typical molecules involved (H – F,O,N)
Water and the Physical States of Matter
Basic States of Matter
Water Density & States of Matter (Hydrogen Bonds & Crystal Lattice in Ice)
State Changes (Melting, Freezing/Solidification, Evaporation/Vaporization, Condensation, Sublimation, Deposition)
Temperature & Pressure in State Changes
Phase Changes
Melting/Freezing Point (0ºC for Water) & Boiling/Condensation Points (100ºC for Water)
Effect of altitude on Boiling Point / Melting Point
Effect on Cooking
The Extraordinary Properties of Water (To know: What they are, how they are connected to hydrogen bonds, how it helps life)
Less Dense as a Solid
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Hydrogen bonds form crystal lattice in solids
Insulation & Floating
High Specific Heat
Hydrogen bonds prevent temperature changes
Maintaining Homeostasis
Ecosystem Stability
High Heat of Vaporization
Hydrogen bonds require energy before breaking up to allow evaporation
Evaporative Cooling (Ocean Cooling / Evapotranspiration) & Greenhouse Effect
Cohesion
Hydrogen bonds make water sticks to itself like a magnet
Hydrophilic Interactions
Surface Tension (Microhabitats for organisms / Cell Tension / Hydrostatic Skeletons / Capillary Action)
Adhesion
Hydrogen bonds make water sticks to other surfaces like a magnet
Leaf water conservation / Capillary Action / Universal Solvent
Water Wonders in Life
Capillary Action & Life
Universal Solvent
Adhesion & Mixtures
Moving the Molecules of Life
Sex & Multicellularity
Photosynthesis & Cellular Respiration
Hydrophobic Interactions
Origin of Life (Microspheres)
Cell Membranes
Protein
Water & Mixtures
Homogeneous vs. Heterogeneous
Level of Analysis
Solutions
Parts [Solvent vs. Solute]
Concentration (IS IN):
Dilute vs. Concentrated
Unsaturated, Saturated, vs. Supersaturated
Solubility (CAN FIT)
Factors: Temperature, Type of Solute, Solvent Quantity/Type
Dissolving Rate: Temperature; Size; Stirring
Rules:
Polar Dissolved in Polar; Non-Polar Dissolves in Non-Polar; Non-Polar and Polar Do not Mix Well
Soluble / Hydrophilic / Polar vs. Insoluble / Hydrophilic / Non-Polar
Mechanisms
Ions & Dissociation
Other Soluble Molecules (Protein & Sugar Solubility)
Types
Aqueous vs. Tinctures
Electrolytes vs. Non-Electrolyte Solutions
Hard vs. Soft water
Other Topics
Freezing Point Depression & Boiling Point Elevation
Effervescence
Suspensions / Colloids / Emulsions
Acidity & Alkalinity & Water
Water Dissociation & Hydroxide vs. Hydrogen (Hydronium) Ions
Acids vs. Bases & Water Ion Concentrations
pH Scale: & Logarithms
Neutrality
pH Indicator
Acids Facts: Common Ion, taste, reaction to indicators, pH range, examples
Bases Facts: Common Ion, taste, texture, reaction to indicators, pH range, examples
Neutralization Reaction & Salts
Precipitate & Precipitation Reactions
Acid & Alkalinity in Biological Systems
Buffers & Biological Function
Acid Rain & Impact on Biological Systems