Karteikarten
Chapter 13: Solutions
Karten in diesem Stapel (68)
- 1entropya measure of energy randomization or energy dispersal in a system
- 2The tendency for energy to _____ whenever it isn't restrained is the reason that two ideal gases mix.disperse
- 3list the forces in a solutionsolvent-solute interactions
solvent-solvent interactions
solute-solute interactions - 4solution generally forms if the solvent-solute interactions _____ the solvent-solvent and solute-solute interactions>=
- 5formation of solution is driven by _____entropy
- 6when solvent-solute interactions are _____ solvent-solvent and solute-solute interactions, a solution may form depending on disparities between interactions. small disparity _____ solution. large disparity _____ solution.<
=
no - 7rule of thumb for predicting formation of solutionlike dissolves like
i.e. polar solvents dissolves polar/ionic solutes - 8E required: endothermic or exothermic separation of solute separation of solvent mixing solute/solvent*endothermic
*endothermic
**exothermic
*for separation
**released as solute/solvent interact - 9enthalpy of solution ΔHˢᵒˡⁿΔHˢᵒˡⁿ = ΔHˢᵒˡᵘᵗᵉ + ΔHˢᵒˡᵛᵉⁿᵗ + ΔHᵐᶦˣ
Units: kJ/mol - 10rule 1: if ΔHˢᵒˡⁿ is about 0- entropy ↑ during mixing = solution
- E of system stays the same - 11rule 2: if ΔHˢᵒˡⁿ is negative- solution process is exothermic
- lower E and greater entropy forms solution - 12rule 3: if ΔHˢᵒˡⁿ is positive- solution process is endothermic
- if not too large, greater entropy forms solution
- if too large, solution doesn't form - 13heat of hydration- aqueous solutions w/dissolved ionic compounds (ΔHˢᵒˡᵘᵗᵉ)
- ΔHˢᵒˡᵛᵉⁿᵗ + ΔHᵐᶦˣ are combined
- large, negative, exothermic
- energy given off when ions are hydrated - 14enthalpy of solution (ΔHˢᵒˡⁿ) w/heat of hydrationΔHˢᵒˡⁿ = ΔHˢᵒˡᵘᵗᵉ + ΔHˢᵒˡᵛᵉⁿᵗ + ΔHᵐᶦˣ
ΔHˢᵒˡⁿ = ΔHˢᵒˡᵘᵗᵉ + ΔHʰʸᵈʳᵃᵗᶦᵒⁿ - 15energy required to separate ionic compounds (ΔHˢᵒˡᵘᵗᵉ) is the _____ of the solute's _____ _____.negative
lattice energy - 16when comparing ΔHˢᵒˡᵘᵗᵉ to ΔHʰʸᵈʳᵃᵗᶦᵒⁿ compare the ______ valuesabsolute
- 17|ΔHˢᵒˡᵘᵗᵉ| ≈ |ΔHʰʸᵈʳᵃᵗᶦᵒⁿ|- same as rule 1
- entropy ↑ during mixing = solution
- E of system stays the same
- doesn't undergo noticeable Δtemp - 18|ΔHˢᵒˡᵘᵗᵉ| < |ΔHʰʸᵈʳᵃᵗᶦᵒⁿ|- same as rule 2
- ΔHˢᵒˡⁿ is negative, exothermic
- warm to the touch - 19|ΔHˢᵒˡᵘᵗᵉ| > |ΔHʰʸᵈʳᵃᵗᶦᵒⁿ|- same as rule 3
- ΔHˢᵒˡⁿ is positive, endothermic
- if not too large, forms solution
- if too large, solution doesn't form
- cool to the touch - 20dynamic equilibriumdissolution rate = recrystallization rate
- 21saturated solution- dissolved solute in dynamic equilibrium with the undissolved solid solute
- no more solute can be dissolved at the same temperature
- Heating solution dissolves excess solute
- Cooling solution forms crystals - 22if we add additional solute to a saturated solution, the solution concentration _____ increase any further.won't
- 23unsaturated solution- a solution containing less than the equilibrium amount of solute
- more solute can be dissolved at the same temperature - 24supersaturated solution- containing more than the equilibrium amount of solute
- unstable
- excess solute precipitates out of solution
- some cases exists for an extended time period - 25solubility of most solids in water _____ with increasing tempincreases
- 26recrystallizationwhen a saturated solution at high temp cools → becomes supersaturated & excess solid precipitates. if it cools slowly → solid forms crystals
- 27solubility of a gas in a liquid is affected by _____ and _____temperature
pressure - 28solubility of gases in liquids _____ with increasing temperaturedecreases
- 29the _____ the pressure of a gas above a liquid, the more soluble the gas is in the liquidhigher
- 30partial pressure (atm) of a gas- Pᵍᵃˢ = Xᵍᵃˢ ⋅ Pressureᵗᵒᵗᵃˡ
- 31Henry's Law formula (solubility of gases w/increasing pressure)Sᵍᵃˢ = kᴴ ⋅ Pᵍᵃˢ
- Sᵍᵃˢ = solubility of gas (M)
- kᴴ =
, specific to solute, solvent, temp
- Pᵍᵃˢ = partial pressure (atm)
- units: M/atm - 32molarity (M)- solute amt / solution volume
- units: mol / L
-depends on volume/temp - 33molality (m)- solute amt / solvent mass
- units: mol / kg
- independent of temp
- useful when comparing concentrations over different temp ranges - 34mole fraction (χ)- solute amt (mol) /
ttl amt of solute & solvent (mol)
- units: none - 35mole percent (mol %)-[solute amt (mol) / ttl amt of solute & solvent (mol)] × 100%
- units: % - 36parts by mass (%, ppm, ppb)- (mass solute / mass solution) × multiplication factor
multiplication factor:
% = 100, ppm = 10⁶, ppb = 10⁹ - 37parts by volume (%, ppm, ppb)- (volume solute / volume solution) × multiplication factor
multiplication factor:
% = 100, ppm = 10⁶, ppb = 10⁹ - 38write conversion factor to show the grams of solution for 3.5% sodium chloride by mass100g solution / 3.5g NaCl
- 39write conversion factor to show the grams of NaCl for 3.5% sodium chloride by mass3.5g NaCl / 100g solution
- 40mole percent (mol %)mole fraction × 100%
- 41colligative propertya property that depends on the number of particles dissolved in solution, not on the type of particle
- 42vapor pressure of the solution is _____ than the vapor pressure of the pure _____lower
solvent - 43Raoult's Lawgives the vapor pressure of a solution
- 44Raoult's Law formulaPˢᵒˡᵘᵗᶦᵒⁿ = Xˢᵒˡᵛᵉⁿᵗ × Pˢᵒˡᵛᵉⁿᵗ
Pˢᵒˡᵘᵗᶦᵒⁿ = vapor pressure of solution
Xˢᵒˡᵛᵉⁿᵗ = mole fraction of solvent
Pˢᵒˡᵛᵉⁿᵗ = vapor pressure of solvent - 45ideal solution- solute-solvent interactions similar to solute-solute, solvent-solvent interactions
- solute dilutes solvent - 46non-ideal solution- solute-solvent interactions stronger or weaker than solvent-solvent interactions
- if solute-solvent > →
solution vapor pressure < than predicted
- if solute-solvent < →
solution vapor pressure > than predicted - 47The freezing point of a solution containing a ______ solute is ______ than the freezing point of the pure solvent.nonvolatile
lower - 48boiling point of a solution containing a _______ solute is _______ than the boiling point of the pure solventnovolatile
higher - 49osmotic pressurepressure required to stop osmotic flow
- 50van't Hoff factor (i)ratio of
moles of particles in solution /
moles of formula units dissolved
factor for FeCl₃ is 4
4 particles (1 Fe + 3 Cl) /
1 formula unit (1 FeCl3) - 51formula for van't Hoff factor (i) & freezing pointΔT = i × m × K
freeze point = solvent freezing point - ΔT
ΔT: freezing point temp change, in C
i: solute van't Hoff factor
m: solution molality
K: freeze point depression constant 4 solvent - 52formula for van't Hoff factor (i) & boiling pointΔT = i × m × K
boiling point = solvent boiling point + ΔT
ΔT: change in temp of boiling point, in C
i: solute van't Hoff factor
m: solution molality
K: boiling point elevation for solvent - 53formula for van't Hoff factor (i) & osmosis pressureII = iMRT
i: solute van't Hoff factor
M: solution molarity
R: ideal gas constant -
0.08206 L ⋅ atm / mol ⋅ K
T: temp in Kelvins - 54like freezing point depression is greater for solutions w/electrolytes as compared to nonelectrolyte solutions, so is the _____ _____ lowering.vapor
pressure - 55name the colligative propertiesVapor pressure lowering
Boiling point elevation
Freezing point lowering
Osmotic pressure - 56solubility depends onNature of solute and Solvent
temperature
pressure
Presence of other solute in the solvent - 57Intermolecular forcesdipersion: Nonpolar solute and solvent
Dipole - Dipole: polar solute and solvent
Hydrogen bond: Solute and Solvent that has H Attached to F,O,N
Ion - Dipole: Polar solvent – Ionic solute - 58Lattice energy is energy released when an _____ _____ is formed. It will be _____. To dissolve solutes we break bonds (endothermic) → _____ sign. ΔHˢᵒˡᵘᵗᵉ → _____ signionic
compound
negative
positive
positive - 59common ionan ion that enters the solution from two different sources
- 60Raoult’s law: Non volatile solutes that don't disassociate into ions- Only solvent escapes into gas phase
- Non volatile solute remain in liquid phase - vapor pressure of solution is lower than pure solvent - 61Raoult’s law: Non volatile solutes that disassociate into ions- Only solvent escapes into gas phase
- Non volatile solute remain in liquid phase - For every one mole of NaCl we get 2 ions - - vapor pressure of solution is lower than pure solvent - 62Raoult’s law: Volatile Solutes- solvent escapes into the gas phase
- volatile solute also escapes into gas phase
- solvent and solute will be on surface → Partial pressure of both must be calculated - 63formula for molar massmoles = gram / MM or
MM = grams / moles - 64explain % dissociation for Van’t Hoff factormeasured value of ‘i’ is smaller than actual value. Value seems to become smaller in concentrated solutions, because of the formation of ion pairs
- 65% dissociation formula% dissociation = [(i - 1) / (iᵐᵃˣ - 1)] * 100
- 66The osmotic pressure of a 0.0100 M KI solution at 25°C is 0.455 atm. Calculate the % dissociation of KI. van't factor of KI = 2 (1K + 1I)π = iMRT
0.455 atm = i x 0.0100 M x
(0.08206 L⋅atm / K⋅mol) x 298 K
i = 1.86
[(i - 1) / (iᵐᵃˣ - 1)] * 100
86% = [(1.86 - 1) / (2 - 1)] x 100 - 67pressure of water760 mmHg
- 68Kᶠ and Kᵇ for waterKᶠ: –1.86° C
Kᵇ: 0.512° C
freezing: 0° C
boiling: 100° C
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- General Chemistry (Chem II) Karteikarten am Chapter 13: Solutions, erstellt von Alexandra Bozan am 10/06/2019.
- Erstellt von
- Alexandra Bozan
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