Who Gets the Proton

What happens when you mix an acid and base, or, worse still, two acids and a base— Who gets the proton Often there s no choice. If there s only one base present (other than water), the base gets the proton. If you add an acid to a mixture of bases, the stronger base takes the proton first. Because we only discuss acid strengths, the stronger base is the one that comes from the weakest acid (has the highest pKa). 

when you add an acid, the amino group, the strongest base, gets the proton first. If you add a base to a mixture of acids, the strongest acid gives up protons first. 

When titrating acids with a strong base, the acids titrate in order of increasing pKa. A carboxylic acid titrates before a protonated amine when strong base is added. 

---

Weak Acids Make Strong Bases (and Vice Versa) Who Gets the Proton ... 

There are several joint ventures, such as the Multi Purpose Vehicles (MPV) that Ford, Nissan, and VW produce exactly the same vehicle with slight modifications. Ford, Seat, and VW also produce a common MPV and there are several partnerships, such as Rover engines being supplied to Proton, Ford, and Honda. Lada get their chassis from Fiat and their engines from GM. Mitsubishi build the Carisma in Holland in the same plant that Volvo build the S40. The Porche Boxster is assembled in Finland by the same company that assembles the Saab 9-3 cabriolet, and so on. One cannot be sure who owns the company that makes your car, where the components come from, and where it is assembled. What matters is that it meets your needs and expectations and this can only be achieved if there are some common systems in use in each of the countries, so that who owns who and who builds what becomes irrelevant to customer confidence. It is reported that within 20 years there may only be six vehicle manufacturers left in the world. ... 

Other workers who have developed or used QM/MM semi-empirical potentials include Bakowies and Thiel, who have discussed the integration of MM polarization into hybrid potentials and have applied their method to study a number of reactions in the gas phase.Bash and co-workers have calculated the free energy profile for the proton transfer between methanol and imidazole in solution. The different aspect of this work was that they reparametrized the semiempirical method to get accurate interactions between the QM and MM portions of the system using a method originated by Rossi and Truhlar.3 ... 

---