Chapter 9: liquids, solids, and solutions

The Rock Cycle

Igneous metamorphic Sedimentary The Rock Cycle

Igneous The Rock Cycle Igneous means “born of fire”

Magma Bedrock

But then the EARTH Won’t leave The poor rock alone!

Ice Wind Water ice water wind

Compression of sediments is One way Sedimentary Rock can be formed

Igneous metamorphic Sedimentary The Rock Cycle ?

Igneous metamorphic Sedimentary The Rock Cycle squished kinda melted

HOT!

Bands (can) form Metamorphic means “changed”

igneous metamorphic Sedimentary The Rock Cycle

liquids  Made up of particles in constant motion  Particles closer together than gases  Less KE than gases

 Definite volume  Fluidity  Relatively high density  Relatively incompressible  Dissolving ability  Ability to diffuse  Tendency to evaporate and boil  Tendency to solidify

Solids (2 types)  Crystalline (crystal): particles in orderly geometric pattern  Amorphous: random arrangement

 Definite shape  Definite volume  Nonfludity  Definite melting point  High density  Incompressibility  Slow rate of diffusion

Changes of state  Solid  liquid (melting)  Solid  gas (sublimation)

 Liquid  solid (freezing)  Liquid  gas: (vaporization)

 Gas  liquid: (condensation)

 Gas  solid: (deposition)

Phase diagram

 Triple point: solid, liquid, gas coexist at equilibrium for water = kelvins (0.01 °C) and a pressure of pascals (ca millibars, atm). for water = kelvins (0.01 °C) and a pressure of pascals (ca millibars, atm).kelvinspascalsmillibars atmkelvinspascalsmillibars atm  Critical temperature: gas can not be converted to a liquid no matter how much pressure is exerted beyond the critical temp. for water =374°C ( K) for water =374°C ( K)

Water cycle

Solutions  Homogeneous mixtures

Electrolyte  Substance that dissolves in water and gives a solution that conducts electric current, e.g. NaCl

Nonelectrolyte  Does not conduct electricity, e.g.sugar  WHY??

Solvent  Dissolving medium

Solute  Substance dissolved

Types of Solutions  1. Gaseous, e.g. air

 2. Liquid, e.g. vinegar

 3. Solid, e.g. brass (solution of copper (solution of copper and zinc) and zinc) + = + =

Alloy  Mixtures in which 2 or more elements (usually metals) are uniformly mixed

Solubility  The amt. of a substance required to form a saturated soln. with a specific amt. of solvent at a given temp.

Effect of temperature  Increase in temp. usually decreases solubility of a gas in a liquid  Increase in temp. usually increases solubility of a solid in a liquid

Solubility of a gas in water

Factors affecting solubility  Types of solvents, solutes  Pressure  temperature

Heat vs. temperature  Temperature is a number that is related to the average kinetic energy of the molecules of a substance. kinetic energykinetic energy  Heat is a measurement of the total energy in a substance

Saturated solution  Max. amt. of dissolved solute

Unsaturated soln.  Less solute than sat. soln

Supersaturated soln  More solute than sat. soln

Suspensions  Heterogeneous mixture, particles settle out, e.g. muddy water

Colloids  Particles intermediate in size between solutions and suspensions, e.g. a cloud

Factors affecting rate of dissolving  Increased surface area  Agitating soln  Heating

Freezing point depression  the difference between the freezing points of a pure solvent and a solution mixed with a solute. It is directly proportional to the concentration of the solution freezing pointssolventsolutionsolutefreezing pointssolventsolutionsolute

Boiling point elevation  a solution will have a higher boiling point than that of a pure solvent after the addition of a dissolved solute solutionboiling pointsolventsolutionboiling pointsolvent

Concentration  Measurement of the amt. of solute in a given amt of solvent

Molarity (M)  The number of moles of solute in one liter of solution molarity = # moles of solute molarity = # moles of solute # L of solution # L of solution

0.500 mol of NaOH is dissolved in enough water to yield 1.00 L of solution mol of NaOH is dissolved in enough water to yield 1.00 L of solution mol NaOH mol NaOH Molarity = 1.00 L soln. = M NaOH

What is the molarity of 2.5 L of soln that contains 80.0 g of NaCl? 80.0 g NaCl x 1 mol NaCl x g NaCl 2.5 L soln 58.4 g NaCl 2.5 L soln = 0.55 M NaCl (M = mol/ L) (M = mol/ L)

How many g of NaCl are needed to make 2,0 L of a 0.40 M soln? 0.40 mol NaCl x 58.4 g NaCl 1 mol NaCl 1 mol NaCl = g/L g x 2.0 L = 47 g NaCl in 2 L soln

Diluting Solutions  (M i ) (V i ) = (M f ) (V f )

You are given a solution of commercially available aqueous ammonia (14.8 M NH 3 ). How many mL of this soln is required to prepare mL of 1.00 M NH 3 when diluted? M i V i = M f V f V i = M f V f M i M i =(1.00M) (100.0 mL) 14.8 M = 6.76 mL

Standard Deviation  Most common measure of statistical dispersion (how widely spread the values in a data set are) statistical dispersiondata setstatistical dispersiondata set  If the data points are close to the mean, then the standard deviation is small  If many data points are far from the mean, then the standard deviation is large

 Standard deviation calculated as follows:  For each value x i calculate the difference between x i and the average value.  Calculate the squares of these differences.  Find the average of the squared differences. This quantity is the variance σ2. variance  Take the square root of the variance.

Water  Most abundant liquid on Earth  70-90% of living mass  Covalent bonds between atoms within molecule  Hydrogen bonds between molecules  Highest density at 4 deg. C  biological/ ecological implications

Structure of water

Crystal structure of ice

Water cycle

JEOPARDY SOLIDSLIQUIDSSOLNSWATER

SCORES  TEAM 1  TEAM 2  TEAM 3  TEAM 4