Types of Intermolecular Forces
Intermolecular Forces: Effect on Solubility Main Idea: “Like dissolves like.” The stronger the intermolecular forces between solute molecule and solvent molecule, the greater the solubility of the solute in the solvent.
• Polar molecules are soluble in polar solvents (Predominant intermolecular force is dipole-dipole attraction between polar solute molecule and polar solvent molecule).
• Nonpolar molecules are soluble in nonpolar solvents (Predominant intermolecular force is London dispersion attraction between nonpolar solute molecule and nonpolar solvent molecule).
• Polar molecules and nonpolar molecules do not mix.
Trends
1. Between two polar molecules, the molecule with the smaller hydrocarbon portion (or the larger polar portion) is more soluble in water.
CH3CH2OH Soluble in water
CH3CH3CH3CH3CH3CH2OH Insoluble in water CH2(OH)CH(OH)CH(OH)CH(OH)CH(OH)CH2OH Soluble in water. Large but many OHs that can hydrogen bond with water.
2. If completely nonpolar, insoluble in water (and soluble in nonpolar solvents).
CH3CH3CH3CH3CH3CH3 Insoluble in water
7. (10 pts) List the intermolecular forces between the compounds in the previous problem and water....
10. (10 pts.) Identify the intermolecular forces present in the following compounds: Compound Intermolecular forces H- N- H H₃C CH₂ ç CC-C1 a. Which compound would you expect to have the higher boiling point? b. Justify your selection. C. Which compound would you expect to have the highest vapor pressure? d. Justify your selection.
The following compounds are given: 7. The following compounds are given: CH₃ H3C-C-CH3 CH₂ Cts o n on OH 1. Which compound will have the lowest boiling point? 2. Which compound will have the highest boiling point? 3. Which compound/s will be soluble in C.H14? 4. Which compound/s will be soluble in water? 5. Which compound has the highest intermolecular forces? 6. Rank all 5 compounds from lowest to highest solubility in water
no intermolecular forces in this substance Question 2 Which of the following compounds will hydrogen bond with water (HO)? Select all that apoly 0 Cala НЕ CH₂O HCN Question 3 Which of the following will have the highest boiling point?
10. (14 pts) For the compounds below: a. Identify the strongest intermolecular force present in each molecule. b. Arrange the following molecules in order of lowest vapor pressure to highest vapor pressure. c. Briefly justify your answer to part b using your knowledge of intermolecular forces. Molecule * HH * Strongest Intermolecular Force: Lowest vapor pressure: < < Highest vapor pressure 11.(12 pts) Ethanol (CH-OH, FW-46.08 g/mol) melts at -114 °C and boils at 78 °C. How much heat is...
What is the only intermolecular force that largely determines the solubility of ionic compounds in water ? the answer is not h bonding ion-dipole forces dipole-dipole forces H-bonding dispersion forces
a) Which type of intermolecular forces accounts for the differences in boiling points in these three compounds? 1) Methanol CH,OH 2) 2-Methylpropane Сн, H₃ C CH₃ 3) Acetone H₃C/ CH3 b) Determine the order of highest to lowest boiling points: Highest bp Lowest bp
For the two compounds below, use chemical structure and intermolecular forces to predict which compound would exhibit greater solubility in water. Use thermodynamics of dissolution in water to frame your answer. HO CH3 НО MW = 110.12 g/mol MP = 105 °C MW = 108.14 g/mol MP = 31 °C
What kind of intermolecular forces act between two water molecules? Note: If there is more than one type of intermolecular force that acts, be sure to list them all, with a comma between the name of each force.
List all of the intermolecular forces that will be present in the following compounds, assuming they are all liquids, and CAPITALIZE (ALL CAPS) the the most dominant force for each liquid. The type of compound is indicated in brackets, and all numbers immediately following elemental symbols should be understood as subscripts. (a) CH3NH2 [polar]; (b) C10H22 [nonpolar]; (c) O2 [nonpolar]
Intermolecular forces (IMPs) are the forces of attraction (or sometimes repulsion) that act between neighboring molecules All IMPs are based on etectrostatic interaction and are relatively weak compared to the Intramolecular forces that hold the atoms within a molecular together. In today, workshop you will practice to identify IMFs and predict their effect on boiling point melting point, vapor pressure and enthalpy of vaporisation (Delta Hvap). The Delta Hvap for a given molecule is the energy required to transform a...