One remedy for a deficiency of vitamin B12 for the elderly is a regular injection of this important nutrient. The vitamin B12 injection dose depends on factors such as gender and age.
Hydrogen bonds happen in alcohols. As a matter of fact, any molecule that contains a hydrogen atom attached to an atom of nitrogen or oxygen is capable of such a bond. Ethanol is one such alcohol that features hydrogen bonds. Ammonia is an example of hydrogen bonding. In the case of ammonia, however, the hydrogen bond happens to be relatively weak.
ethanol: hydrogen bonding; acetic acid: hydrogen bonding; van der Waals; van der Waals Now do Exercise 9. For each set of three chemicals, put them in order from strongest to weakest intermolecular bond type, and from highest to lowest melting and boiling points. Answers to Exercise 9: (The strongest bonding will lead to the highest melting and boiling points. In each case, the first compound has intermolecular hydrogen bonding, the middle compound has dipole-dipole bonding, and the final molecule has van der Waals bonding.) Exercises 7, 8, and 9 dealt only with intermolecular bonds.