Fichas
Chapter 11 - Test One
Fichas del conjunto (39)
- 1If a nonvolatile solute is added to a liquid (solvent) at equilibrium its vapor =the liquid-to-gas rate is (increased/reduced/unchanged) since there are fewer solvent molecules at the surface
reduced - 2The gas-to-liquid rate is initially (increased/unchanged/reduced).Unchanged, VP will decrease
- 3Raults law P = vapor pressure X = mole fraction P0 = vapor pressure of the pure solventPsolution=XsolventP0solvent (since the solution is nonvolatile, P solution= P solvent)
- 4An ideal solution is a solution that obey's Raolt's Law .In an ideal solution, the strength of the solute-solvent interactions is equal to that of solvent-solvent interactions. For solvents, this is a good assumption at mole fractions close to 1.
- 5Gas solubility (increases/decreases) as the partial pressure of that gas increases.Increases; more gas, more collisions more will go into solution with surface
- 6At equilibrium, rates of solvation and gas formation are unequal/equalequal
- 7As the gas pressure increases, there are more collisions of gas molecules with the solvent which increases/decreases the rate of solvation.Increases (more gas goes into the solution)
- 8Henry's lawCgas =kHPgas
Cgas=concentration of the gas in solution
kH = Henry's law constant (different for each gas-liquid system) - 9The value of kH depends on the 1. 2. 3.gas solvent and temperature
- 10Gas solubility (increases/decreases) as T increasesdecreases (raise temp, more energy needed to overcome IMF)
- 11Liquid and solid solubilities tend to (increase/decrease) with increases in T.increases; more solid goes into solution, high temperatures prefer to be liquid
- 12Liquid and solid solubilities are (dependent/independent) of Pindependent
- 13Small, highly charged ions attract each other strongly. This gives their compounds higher melting points (harder to pull apart). The strength of this interaction is quantified as....lattice energy.
- 14The enthalpy of solution is the change in enthalpy when a solute dissolves in a solvent. This can be readily measured and used to determine enthalpy of formation of ions. The magnitude (can/can't) be predicted by lattice energy.can't
- 15Fractional Distillation =as a mixture is heated, the vapor contains a larger fraction of the more volatile component. as this vapor condenses and then boils again and the new vapor has even a larger fraction of the more volatile component.
- 16colligative propertiesdepend on the quantity of but not the kind of solute particles
- 17Assumes all particles (molecular or ionic, charged or uncharged) have the same effect. Ionic compounds break into ions in solution, each of which is assumed to act invidiually.Colig properties dependent on number of particles
- 18ex. of colligative propertyvapor pressure lowering (raoults law)
- 19At a pure liquid's boiling point, its vapor pressure must equal theexternal pressure
- 20Adding nonvolatile solute lowers the vapor pressure of the liquid (solvent). Thus, the solution is (boiling/not boiling)not boiling
- 21T must be increased in order to increases the vapor pressure until it equals the external pressure. The boiling point (increases/decreases) when solute is added.increases
- 22vapor pressure lowering also results in the lowering/increase of freezing pointlowering (vapor pressure of solid/liquid must be equal at freezing point)
- 23Boiling pointebullioscopic sonstant, but is commonly called the boiling point elevation constant C/m (molal)
- 24Kfcryoscopic constant, but is commonly called the freezing-point-depression constant
- 25The advantage of molalityindependent of temperature (molarity depends on volume of solution, which changes slightly when T changes)
- 26For dilute aqueous solutions, one liter has a mass of approx.one kg, so m ~ M
- 27All solute particles will have equal effectsIf a solute forms multiple particles when it dissolves, the effect will be increased proportionally
- 28Osmosisflow of solvent (water) through a semi-permeable membrane from less to more concentrated (solute particles can't flow through membrane often due to size)
- 29Flow occurs because the less concentrated solution has a (higher/lower) vapor pressure and evaporates (more/less) easily and, thus is (more/less) stable. The flow will stop when the concentrations on both sides of the membrane are equal.Higher, more, less
- 30osmotic pressurepressure required to prevent the flow of solvent molecules from a less concentrated to more concentrated
- 31Pi=nRT or Pi=iMRTosmotic pressure equation
- 32isotonic solutionssolutions that have the same osmotic pressure
- 33hypotonic- lower osmotic pressure, blood cells in such a solution with swell/shrivelswell
- 34hypertonic-higher osmotic pressure, cells will shrivel/swellshrivel or crenation, dilute surroundings
- 35dialysisseparation of small and large solute particles by diffusion through a semi-permeable membrane
- 36reverse osmosisapplication of pressure to force solvent through a semi-permeable membrane, leaving the solute behind in order to purify the solvent
- 37The magnitude of any colligative property is dependent on the blank of the solute.concentration; hence by measuring the change in the property, we can determine the concentration. Knowing the grams of the solute used and the concentration, we can determine the molar mass.
- 38Best colligative property for aqueous solution is osmotic pressure because: 1. 2. 3.1. there are large charges in osmotic pressure even when only small amounts of solute are used
2. experimental technique is precise
3. material can generally be recovered after experience - 39For all colligative properties, the addition of the solute has increased the stability of the solvent, it is less likely to... 1. 2. 3. 4.1. evaporate (Rauolts Law) 2. Boil (Bp elevation) 3. Freeze (fp depression) 4. flow through a membrane (osmosis)
Información
- Descripción
- Chem 123 Fichas sobre Chapter 11 - Test One, creado por Hannah Tobiczyk el 27/01/2015.
- Creado por
- Hannah Tobiczyk · ene 2015
- Actualizado
- 19 feb 2016
- Visitas
- 2
- Valoración