Chapter 2: Water, weak acids, bases, and buffersLearning objectives(Important topics are highlighted in red)1. Know the structure and properties of water- Single oxygen covalently bonded to two hydrogen atoms- 104.5 degrees between hydrogen atoms- Properties?2. Understand what are hydrogen bonds and how are hydrogen bonds formed- Dipole-dipople attraction between molecules- The slightly positive hydrogen of one water molecule is attracted to the slightly negativeoxygen of another water molecule (or another electronegative atom of another molecule)3. Know the properties of hydrogen bonds: directional and saturable. Know the bond energy ofhydrogen bonds and covalent bonds- Hydrogen bond energy: 23 kJ/mol- Covalent bond (O-H): 470 kJ/mol4. Understand the different kinds of noncovalent bonds among biomolecules- Ionic interactions: 86 kJ/mol?- Van der Waals forces: the chart is confusing?- Hydrogen bond: 20 kJ/mol- Dipole-dipole interaction: 9.3- London dispersion forces: .35. Understand the physical properties of amphipathic molecules and their significance in biology- Amphipathic molecules are chemical compounds that have both polar and nonpolarregions, giving them both hydrophilic (water-loving) and lipophilic (fat-loving)properties- They are important in the formation of biological membranes and micelles- They create a barrier so not all substances can enter/exit the cell- Amphipathic compounds form special structures in aqueous solutions6. Understand what are the colligative properties of solutions- Boiling point- Freezing point- Vapor pressure- Osmotic pressure- These all depend on the number of particles (ions or molecules) in the solution7. Understand what is osmotic pressure and be able to calculate osmotic pressure using the van’tHoff equation- the pressure that would have to be applied to a pure solvent to prevent it from passinginto a given solution by osmosis, often used to express the concentration of the solution.- Van’t Hoff equation: π = ic[RT]- ic = osmolarity- R = gas constant- T = temperature in K8. Understand what is dialysis and what are hypertonic, isotonic, and hypotonic solutions- the separation of particles in a liquid on the basis of differences in their ability to passthrough a membrane- Hypertonic solution: high solute concentration- Isotonic solution: equal concentration- Hypotonic solution: low solute concentration9. Understand the definition of pH and be able to calculation pH, [H+], and [OH-] of solutions- pH: way to specify acidity or basicity of an aqueous solution- pH = log [1/H+] = - log [H+]- Idk the rest man10. Understand the BrÆnsted acid and base theory and what are conjugate acid base pairs- An acid is a proton donor, a base is a proton acceptor- The pair consists of two substances that differ only by the presence of a proton H+11. Understand the theoretical definition of dissociation constant (Kaand pKa) of weak acids- uh12. Be able to calculate pH of weak acids solutions using the Henderson-Hasselbach equation13. Understand what are buffers and be able to calculate pH of buffer solutions using theHenderson-Hasselbach equation. Know how to make buffer solutions- Buffers are solution that tend to resist the changes in pH when small amount of acid orbase are added to it- A buffer system contains a weak acid (proton donor) and its conjugate base (protonacceptor), or a weak base with its conjugate acid- See equation from #1214. Know the buffer systems in cells and blood and understand how do they work- Buffering in the cell: the phosphate buffer system- H2PO4- ← → HPO42- + H+- Buffering for blood: the bicarbonate system- H2CO3 ← → H+ HCO3-- Coming back to this one16. Understand the titration curve of phosphoric acids and the experimental meaning of pKa1,pKa2, and