Gold parting of the salt cementation process. This mixture is then added to an earthenware pot and layered with thin sheets of gold fold. The pot is then sealed and heated in a furnace. It was during the medieval period that distillation was discovered and the first description of nitric acid production was given by Pseudo-Geber in the "Summa perfectionis", 1330. Nitric acid is able to dissolve silver. The addition of sal ammoniac to nitric acid creates Aqua regia and this acid is able to dissolve gold. Both acids are used in the acid method of parting but the acids were expensive
Brønsted–Lowry acid–base theory to become its conjugate base, A. The base, B, can accept a proton to become its conjugate acid, HB. Most acid-base reactions are fast so that the components of the reaction are usually in dynamic equilibrium with each other. Consider the following acid–base reaction: Acetic acid, CHCOOH, is an acid because it donates a proton to water (HO) and becomes its conjugate base, the acetate ion (CHCOO). HO is a base because it accepts a proton from CHCOOH and becomes its conjugate acid, the hydronium ion, (HO). The reverse of an acid-base reaction is also an acid-base reaction, between the