Category: Simplified Chemistry

amperometric titration : A method of determining the chemical composition of a solution by measur­ing the current passing through a cell containing the solution; the po­tential is held constant during the titration for both the indicator and reference electrodes, with changes in the current being measured. The cur­rent flowing through the cell is meas­ured as

ammonia clock A form of atomic clock in which the frequency of a quartz oscillator is controlled by the vibrations of excited ammonia molecules. The ammonia molecule (NH3) consists of a pyramid with a ni­trogen atom at the apex and one hy­drogen atom at each corner of the triangular base. When the molecule is excited,

Describing a conjugated molecule in which the atoms can be divided into two sets of alternate atoms such that no atom has a direct link to another atom in the same set. Naphthalene, for example, has an al­ternant conjugated system.