Question

Order the three types of intermolecular forces: dipole-dipole, London force, hydrogen bonds in terms of strength from weakest to strongest. Give a brief description of each of the different intermolecular forces. Question 24 (6 points) The boiling points for H2O (BP = 100°C) and HS (BP-60°C) are drastically different despite oxygen and sulfur being next to each other on the periodic table. Explain these differences in boiling points utilizing your labels of intermolecular forces and the relative strength of the intermolecular forces. Question 25 7 points) Hydrogen bonds are extremely important in biological molecules, give an example of a biological biochemical molecule that utilizes hydrogen bonding Explain what needs to happen for the hydrogen bonds to be present in your example? (Note: Wat is not a good example of a bolocal molecule)

Answer 1

solution: in terms of The forces order of strength intermolecular forces from from weakest to strongest London force < dipole - dipole < Hydrogen bond Weakest strongest - London forces: the It is weakest intermolecular forces. The disp. london ersion forces is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms from form temporary dipoles. This force is sometimes called an induced dipole - induced dipole attraction London forces are the attractive forces es that cause nonpolar substance to condense to liquids and to freeze into solids when the temperature. is lowered sufficiently. Dipole-dipole Dipole - dipole forces are attractive forces between the positive end of one polar molecule and the negative end of another polar molecule. Dipole-dipole forces have strengths that range from 5 kJ to 20kJ per mole. They are much weaker than ionic or covalent bonds and have a significant effect only when the molecules involved are close together. e.g StI-cld- s.cl - I St

Hydrogen bond A hydrogen bond is a partial intermolecular bonding interaction between a lone pair on an electron rich donor atom, particularly the second row elements nitrogen, oxygen or fluorine, and the antibonding orbital of a bond between hydrogen and a more electrone qutive atom or group. There are two type of hydrogen bond. I Intramolecular hydrogen bond, OH e hydrogen bond. e. g t . # Intermolecular hydrogen bondo eg 2- I