Question
please answer all
7. According to Raoult's law, which statement is false? A f e faction A) The vapor pressure of a solvent over a solution decreases as its mole fraction. increases B) The solubility of a gas increases as the temperature decreases C) The vapor pressure of a solvent over a solution is less than that of pure solvent. D) The greater the pressure of a gas over a solution the greater its solubility. E Ionic solutes dissociate in solution causing an enhancement of all colligative. B Ionic solutes dissociate in solution causing an enhancement of all properties. Section: 12.6 8. A solution of chloroform, CHCls, and acetone, (CHs).CO, exhibits a negative deviation from Raoult's law. This result implies that A) chloroform-chloroform interactions are stronger than chloroform-acetone nteractions chloroform-chloroform interactions are weaker than chloroform-acetone nteractions B) C) acetone-acetone interactions are stronger than chloroform-acetone interactions. D) acetone-acetone interactions are weaker than chloroform-acetone interactions. E) Both B and D. F) Both A and C Section: 12.6 hiloroform acetone interacfions. 9. During osmosis A) pure solvent diffuses through a membrane but solutes do not. B) pute solutes diffuse through a membrane but solvent does not C) pure solvent and a solution both diffuse at the same time through a membrane. D) gases diffuse through a membrane into a solution and build up pressur Section: 12.6 e through a membrane into a solution and build up pressure 10. The solubility of gases in water always decreases with increasing temperature. A) True B) Ealsc C) Unknown Category: Easy Section: 12.4 11. For water Kf= 1.86°C/m. Therefore, the freezing points of 1.0 M aqueous KCl and C HsOH (ethanol) solutions are the same. A) True B) Falsc C) Unknown Section: 12.7 12. The solublity of a solid aways increases with increasing solvent temperature. A) True B) False C) Unknown
Explanation / Answer
1) Raoults law states that the relative lowerig of vapor pressure is equal to mole fraction of solute. Both A, B, C are as per Raoults law where as D is with reference to Henrys' law while Colligative properties are to do with the number of solute particles. Hence D and E are incorrect.
2. In case of negative deviations, the vapor pressure is less than that predicted by Raoults' law is. These are cases where the molecules break away from the mixture less easily than they do from the pure liquids.Hence chloroform- Chloroform interactions are stronger than chloroform interactions (A) and acetone-acetone interactinos are strongers than acetone-chloroform interactions.
3. during Osmosis, pure solvent diffues through the membrane not the solute
4. Gases solubility decreases with an increase in temperature. (True)
5. delT= Kf*m where m= molality and thsi depends on molecular weight of solute So even though Molarity is same, their molalirys are different ( False)
7. There are some solids whose solubility decreases with increasing solvent temperaute and these are named as inverted solubilty curves ( False)
