Answer Happy

7. If the solution in (4) was created by dissolving 16.52g of
unknown in 42.3g benzene, calculate the molecular weight of the
unknow compound in g/mol.
5. Liquid nitrogen, which boils at -196 °C, is used in some specialty ice cream shops to freeze ice cream nearly instantly. Modem factories commonly use liquid ammonia as refrigerant to freeze ice cream at around -30°C. Before liquid ammonia was available, mixtures of water and table salt (NaCl) were used. Adding salt to water can lower its freezing point to as low as -21.1°C. What is the molality of a salt water solution with this freezing point? Water has a Kr of 1.86 °C/m and a freezing point of 0.0°C. A corollary colligative property to freezing point depression is boiling point elevation. In this case, a solution will begin to boil at a higher temperature than its corresponding pure solvent from the following equation: ATb = * K *m Here, AT. is the increase between the pure solvent and the solution boiling points, i is the van't Hoff factor for the solute, Kh is the molal boiling point elevation constant individual to the solvent, and m is the solution's concentration in units of molality. 6. Benzene has a Ko of 2.53 °C/m and a normal boiling point of 80.2 °C. Calculate the molality of a solution of benzene and an unknown nonelectrolyte compound that boils at a temperature of 95.6 °C. 7. If the solution in (4) was created by dissolving 15.62 g of unknown into 42.3 g benzene, calculate the molecular weight of the unknown compound in g/mol.

POLAND NETH TI GERMANY nelland +1 REPOSLOVE * Paris Kyiv UKRAINË MOLDOVA AUS (HUNG FRANCE ROMANIA ORTH ANTIS СЕАН Experiment 22-Post-Lab Assignment Name U А. WHY Mounas 1. Is freezing an exothermic or endothermic process? Freeting is an exoner mil process when water solicies it releases heat warming 2. did the outside of the freezer bag get wet? Assume that your bag did not leak. The outside of the weeker wan get wet necause of condensatim, me maker muutes in the air ad cold ou side of bing slow down, juin lunemer and come drydels of water. 3. Describe the transfers of energy that occurred while you were shaking. EM BOL M a. Between air and large freezer bag. Heat flowed from to b. Between the ice and salt mixture and the ice cream bag. Heat flowed from to c. Describe one more transfer of energy that occurred: 52 4. Ice cream doesn't freeze solid at 0 °C: Why not? la cream doesn't fict 7c solid because it has vower meeting point than water. Ice cream has many more parnicles and me waker in the lul enam has a warder nime becoming solid. This is freezing point depression. when we owering of the freezing part of a ligurd by adding strong electrolytes como dete completely dissociate into separate ions when dissolved in aqueous solution. Each ion adds to the number of moles of solute, which in turn increases the change in freezing point. The vant Hofffactor (), is equal to the number of moles that 1 mole of solute becomes when dissolved in solution. A nonelectrolyte, such as C.H.,Os, would have i = 1. A strong electrolyte, such as Znch, would have i = 3 (from Zn2 and 2 CH). The equation for freezing point depression should also include the van't Hoff factor: AT, = 1 *K* m 22-4