Formulas, dualistic

Cu0,S03 is what chemists would now write as CuSO or copper(II) sulfate. However, the dualistic formula does show the composition of the salt from a base and an acid. It may be strange to think of chemical formulae in this way, but consider these two alternative versions of the thermal decomposition of copper(II) carbonate ... 

If we consider metals from the Mn—Zn series, chlorides and sulfates are readily soluble, but chloride ions may act as poisons for the active phases [89] and sulfate ions do not decompose at moderate temperatures. However, their presence is sometimes searched for due to the acidity they can induce on the support [90]. The most used precursors are metal nitrates sold under the dualistic formula M(N03)x.yH20, which associate a high solubility (respectively, 8.5 and 4.6 mol per 1 of water at room temperature for nickel or cobalt, respectively) to the possibility of decomposing nitrate ions by calcination between 250 and 350°C [91]. Carboxylates such as formates or acetates have been sometimes used, thou they are more than three times less soluble than nitrates [92]. These anions also have coordinative properties toward the cations in solution or in the crystals, as is the case for the acetylacetonate anion, which gives precursors soluble in organic solvents. 

In accordance with the dualistic views of earlier days, the composition of sulphuric acid was at one time expressed by the formula H20.S03, but to-day the formula SQ2(OH)2 is generally adopted, commonly with the assumption of sexavalent sulphur, so that the structural formula is... 

In 1917 Einstein [18] wrote a paper on the dualistic nature of light in which he discusses emission without excitation from external causes, in other words stimulated emission and also spontaneous absorption and emission. He derives Planck s formula but also discusses the recoil of molecules when they emit photons. It is the latter discussion that Einstein regarded as the most significant aspect of the paper If a radiation bundle has the effect that a molecule struck by it absorbs or emits a quantity of energy hv in the form of radiation (ingoing radiation), then a momentum hvlc is always transferred to the molecule. For an absorption of energy, this takes place in the direction of propagation of the radiation bundle for an emission, in the opposite direction. ... 

Simple relationships between molecular topology and reactivity can also be derived from the Clar formulae [20] of benzenoid hydrocarbons. For example, in a series of isomeric hydrocarbons the system with the largest number of inherent 7t-sextets is always the least reactive one. Due to the correspondence between number of 7i-sextets in Clar formulae and number of 120° angles [21] in the dualist graphs [22] of benzenoid hydrocarbons a similar relation holds for the dualist graphs. 

Vanaditim — Combining Proportions — Symbols and Formulae — Corpuscular and Volume Theories — Atomic Weis ts — Dualistic Theory—Electrochonical Theory. 

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