2.2 Properties of Water2.2 Properties of Water
WaterWater
•H2O, H-O-H•H2O, H-O-H
•Polarity – one region of molecule is more+ and other end is more - ; overall neutral•Polarity – one region of molecule is more+ and other end is more - ; overall neutral
- Allows water to be an effective solvent - Allows water to be an effective solvent
- It dissolves other polar substances, butwon’t dissolve nonpolars - It dissolves other polar substances, butwon’t dissolve nonpolars
•Hydrogen bonds – weak•Hydrogen bonds – weak
- Bonds that hold water moleculestogether - Bonds that hold water moleculestogether
- + attracted to – - + attracted to –
Cohesion –Cohesion –
- Attraction between molecules of the samesubstance- Attraction between molecules of the samesubstance
Adhesion –
- attraction between molecules of differentsubstances
•Heat capacity•Heat capacity
- The amount of heat energy needed toraise temperature - The amount of heat energy needed toraise temperature
- High for water - High for water
MixturesMixtures
•Mixtures –•Mixtures –
- Made of 2 or more elements orcompounds that are physically mixed butnot chemically combined - Made of 2 or more elements orcompounds that are physically mixed butnot chemically combined
- Ex. Solutions and suspensions - Ex. Solutions and suspensions
•Solution –•Solution –
- All parts are evenly dispersed - All parts are evenly dispersed
- Made of: - solute (substance being dissolved) - Made of: - solute (substance being dissolved)
- solvent (substance where solutedissolves)- solvent (substance where solutedissolves)
•Suspension –•Suspension –
- Mixture of water and nondissolved material - Mixture of water and nondissolved material
Acids, Bases, & pHAcids, Bases, & pH
Acid –Acid –
- Substance with more H+ than OH- - Substance with more H+ than OH-
Base –
- Substance with more OH- than H+
•pH scale – range 0-14•pH scale – range 0-14
•0-6 = acid (red)•0-6 = acid (red)
•7 = neutral•7 = neutral
•8-14 = base (blue)•8-14 = base (blue)
•Buffers –•Buffers –
- Substances that help neutralizestrong acids and bases- Substances that help neutralizestrong acids and bases
