1、List the electronegative atoms,in decreasing order,that can participate in H-bonding.

题目

1、List the electronegative atoms,in decreasing order,that can participate in H-bonding.
2、What are two kinds of attractive forces that can exist when ionic species are present?
3、Give two properties of molecules that are affected by H-bonding and explain how H-bonding affects these properties.
4、Draw the H-bonding in H2O,CH3OH,and HF.
5、The boiling point of H2O (100oC) is much higher that of HF(-83oC),even though they both form H-bonds and have similar molecular weights.Explain.

答案

1.F>O>N>>Cl
2.cation-anion electrostatic and ion-dipole forces.
3.boiling point which increases with effectiveness of H-bonding between like molecules,and solubility,which increases with H-bonding between solute and solvent molecules.
4.H-O-H...O(H)-H...O(H)-H.
CH3-O-H.O(H)CH3
H-F...H-F...H-F
5.One molecule of HF H-bonds at the most with two other molecules,but each H2O molecule contributes both H's for H-bonding with the O's of two other molecules,and uses its O for H-bonding with an H of a third molecule.