Processed foods that are made from both polar and nonpolar ingredients often include at loast one ingredient called an "emulsifier to provent separation during storage. Lecithin is an emulsiher used in many commercial salad dressings. The picture below shows its molecular structure. Use its structure and your knowledge of polarity and its effect on liquid miscibility to explain how lecithin prevents the vinegar and oil in salad dressing from soparating. Mote Vinegar is a diute solution of acetic acid in water. Molecular structure of lecithin HC-0-6 -CH -CH, -CH, CH CH CH, CH, CH CH, CH, CH CH CH CH-CH, -CH CH, H-06-CH, CH CH, CH CH, CH CH, -CH, CH, -CH -CH- CH -CH, CH-CH,

Join In, Question 1 When KCl dissolves in water, what types of intermolecular bonds are formed? KC1= potassium chloride Molar mass=74.5513 g/mol ion-ion ion-dipole hydrogen bonds ion-ion forces and H-bonds K² = positive charge C1 = negative charge ☐ Copyright ©2019 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.

C. Explain the importance polarity of molecules to biological processes such as in the structure of proteins and phospholipids.

PART III: Intermolecular Forces 1. Heat of Formation of one isolated water molecule 2. Heat of Solvation of water 3. Strength of a hydrogen bond (by comparison of #1 and #2 above) 4. Bond Lengths Long O------H Draw the two H-bonded molecules Intermolecular bond Short O-H Intramolecular bond 1. Heat of Formation of one isolated ammonia molecule 2. Heat of Solvation of CH3OH 3. Strength of a hydrogen bond (by comparison of #1 and #2 above) 4. Bond Lengths Long O------H Draw the two H-bonded molecules Intermolecular bond Short O-H Intramolecular bond 1. Heat of Formation of one isolated methane molecule 2. Heat of Solvation of CSH12 3. Strength of intermolecular attractions (by comparison of #1 and #2 above) 4. Bond Lengths Long C------H Intermolecular bond Short C-H. Intramolecular bond Comment on the Strength of intermolecular attractions between H20 and water solvent, CH3OH and CH3OH solvent, cyclohexane and cyclohexane solvent.

Why is CaSO4 less soluble in water than NaCl?

6. Capsaicin is responsible for the heat of peppers. It is common practice to fry capsaicin in oil prior to eating. Which part of the capsaicin molecule forms intermolecular attractive force with oil, a nonpolar solvent? capsaicin C. Он a N. b. a. a b. b C. C d. d

e. The average human skin cell f. The length of the tip of your thumb (measured from first knuckle to the edge of your nail) 2. Consider two molecules, X and Y. a. X is able to dissolve in water. What does this imply about the favorability of interactions between molecules of X versus interactions between X and water? b. Y is unable to dissolve in water. What does this imply about the favorability of interactions between molecules of Y versus interactions between Y and water? Draw what happens to Y in water. 1

HW8 #6

1. The ice cream made in an old-fashioned way is where the maker has a tub full ofmixed ingredients immersed in a bigger tub filled with ice and salt. Why do you think issalt added to the ice? 2. Which would increase more the boiling point of water: salt or sugar? Why?

Why can water dissolve NaCl but hexane cannot?