Card Set Information

2012-05-20 00:06:28
solution chem

solutions chem test
Show Answers:

  1. components o solution (2)
    • solvent - medium solute dissolved in
    • solute - substance tt is dissolved in solvent e.g. salt
  2. types o solutions (4)
    • gas in gas
    • gas in liquid
    • liquid in liquid
    • solid in solid
  3. aqueous solution
    • solutions in which water is solvent
    • transparent but can have colour
  4. polar molecule
    • molc w/ uneven distribution o electrons
    • positive charge one side, negative other
    • water
  5. non-polar molecule
    • molc which electrons even distributed among atoms, no charge
    • carbon dioxide
    • polar covalent bond can exist but no partial charge
  6. intermolecular force
    attractive force BETWEEN molc
  7. intramolecular force
    forces inside molc
  8. strength o intermolc forces determine what physical properties o molec compounds (6)
    • physical state
    • melting point
    • boiling point
    • surface tension
    • hardness and texture
    • solubility in various solvents
  9. What happens as intermolec frcs increase?
    • compound's melting point
    • boiling point
    • surface tension all increase
  10. list names intermolec forces (3)
    • london dispersion forces
    • dipole-dipole forces
    • hydrogen bonds
  11. dipole-dipole forces
    • intermolec frc attrtaction forms b/twn slightly positive end o one polar molc and slightly neg end another polar molc
    • relatively strong
    • occur between all polar molc
    • more polar a substance, stronger dd force o attraction
  12. london dispersion forces
    • weak attractive force acting between all entities caused by temp imbalance electrons
    • larger mol = more electrons/protons = stronger orces = higher melting pointf
  13. hydrogen bonds
    unusually strong dipole dipole force b/twn hydrogen atom and FON, fluorine, oxygen nitrogen
  14. What is frc called that combines dipole dipole and LDF?
    • van der waals forces
    • weak forces attraction between molc, includes ddf and ldf
  15. concentration
    quantity o given solute in solution
  16. dilute
    having relatively small quantity solute per unit vol o solution
  17. concentrated
    having relatively large quantity o solute per unit vol o solution
  18. 3 types percentage concentration?
    • percentage weight by volume, g/100 ml
    • percentage volume by volume, ml/100ml
    • percentage weight by weight, g/100g
  19. mass of solution is?
    mass solute + mass solvent
  20. How do you determine if dipole dipole frces are present?
    • if there's uneven uneven charges
    • if uneven charges cancel out, CO2, O2, no dipole dipole but can still be hydrogen bonding
    • use electroneg for EACH bond
  21. Which compounds dissolve better?
    molc compounbds w/ many hydrogen bonds
  22. Why is water liquid at room temp?
    strong intermolc forces
  23. Why water successful solvent?
    • small in size, highly polar, capcity for hydrogen bonding
    • =signif for life on earth
  24. High melting/boiling point allows
    • exist as liquid at room temp
    • keeps body fluids liquid over large range temps
  25. cooling o water?
    • ice to float
    • water freezes top to down allows life underneath
  26. hydrogen bonds
    • pulls water into round droplets
    • high surface tension
    • allows water walking
  27. inability to dissolve non-polar compounds
    • enables organisms to retain water (wax on leaves)
    • allows organisms to store non-polar substances (fats, oils)
  28. dissociation
    separation o ions tt occurs when ionic compound dissolves
  29. 5 step dissociation process w/ water explain
    • 1. water molc approaches crystal = reorient themselves b/c negative end water attracted to positive end ionic solid
    • 2. water-ion attractions pull ions away from crystal while ionic bonds hold ions together
    • 3. a) if attraction b/twn water and ionic solid = stronger than ionic bonds within ionic solid = dissolve
    • b) if not no dissolve
    • 4. as ions leave leave crystal, surrounded by sphere water molc so can't attract each other again
  30. Which substances don't dissolve well in water?
    • hydrocarbons b/c large, covalent bonds & non-polar
    • no attractive forces between water and hydrocarbons
    • other non-polar substances soluble in hydrocarbons
    • L-D forces loosely attract solute molc to hydrocarbon allowing it dissolve
    • bigger substances = bigger LD frcs
  31. Why do solutes dissolve?
    when attractive frcs b/twn solute and solvent = stronger than attractive frcs within either solute/solvent
  32. molar concentration formula?
    • C n V triangle
    • C V Vsolv
    • CWVsolv
  33. molar concentration
    #moles solute dissolved in 1L solution
  34. dilution
    process decreasing concen o aq solution by adding more water to small amount initial concentrated (stock) solution
  35. formula for dilution questions?
    • C1V1=C2V2
    • ensure constant units
  36. how to calculate grams o substance needed for stock solution?
    • find mole amount, CV = n
    • find grams, nM = m
  37. solubility
    max. amnt solute tt'll dissolve in givent amnt solvent, unit usually g solute/100 mL o solvent
  38. unsaturated solution
    solubility lvl o solvent hasn't been reached and if more solute added, will cont. to dissolve
  39. saturated solution
    solubility lvl o solvent just been reached and if more solute added = no dissolve
  40. insoluble compounds
    compounds w/ low solubility very little solute will dissolve 0.0001 mol/L
  41. soluble compounds
    coumpounds w/ high solubuility lots o tt compound will dissolve 10.0 mol/L
  42. 3 factors that affect solubility
    • molecule size
    • temperature
    • pressure
  43. molecule size
    smalled molc often more soluble than bigger molc
  44. temperature
    • depends on state
    • solids- solubility most solids increase w/ temp, increase temp = molc move faster causing solvent molc to hit solute molc more often breaks them apart faster
    • e.g. molecular, ionic
    • liquids - not generally affected by temp
    • gases - solubility gas decrease w/ high temp, trapped gas molc more opportunity to escape solvent
    • inverse linear relationship
  45. pressure
    • solubility gas dependent on pressure gas above liquid
    • gas molc will move fr area high pressure to lower so if pressure outside solvent = higher, gas dissolves in
  46. temp effect on polar molc, non polar
    • polar liquids solubility increase w/ temp
    • non-polar dont dissolve, immiscible (forms separate layer)
    • liquids w/ small amounts polar molc w/ hydrogen bonding dissolve in water, miscible (mix well in all proportions)
    • elements have low solubility in water e.g. carbon
    • halogens & oxygen dissolve to very tiny extent still reactive in small concentrations
  47. total ionic equation
    • chemical equation tt shows all high solubility ionic compounds in their dissociated form
    • e.g. AgNO3(aq) + NaCl(aq) -> NaNO3(aq) + AgCl(s)
    • Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) -> Na+(aq) + NO3-(aq) + AgCl(s)
    • rewrite w/ charges, solids don't have
  48. spectator ions
    entity tt doesn't change or take part in chemical reaction
  49. net ionic equation
    • way o representing reaction by writing only ions or neutral subst specifically involved in overall chemical reaction
    • Ag+(aq) + Cl-(aq) -> AgCl(s)
    • cross out spectator ions
  50. What happens when two aqueous ionic compounds mixed?
    • compounds remain in solution, no reaction
    • one reactions with other -> precipitate, formation gas, or formation water (H+ and OH-)
  51. how to find concentration ions in solution?
    • write with total ionic equation
    • always convert mL to L
    • use table
  52. what is used for very small concentrations?
    • parts per million
    • 1 ppm = 1g/10^6 mL
    • 1mg/L
    • 1 ug/g
    • 1g/ 1000L
    • 1 mg/kg
  53. what does M for solution represent?
  54. if the question is asking for mass and solution what to do?
    • mass/volume
    • molar mass/ [ ]