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  2. Hume-Rothery rules - Wikipedia

    en.wikipedia.org/wiki/Hume-Rothery_rules

    [5] [6] The solute and solvent should have similar electronegativity. [7] Valency factor: two elements should have the same valence. The greater the difference in valence between solute and solvent atoms, the lower the solubility.

  3. Valence (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Valence_(chemistry)

    Thus, each sulfur atom is hexavalent or has valence 6, but has oxidation state +5. In the dioxygen molecule O 2, each oxygen atom has 2 valence bonds and so is divalent (valence 2), but has oxidation state 0. In acetylene H−C≡C−H, each carbon atom has 4 valence bonds (1 single bond with hydrogen atom and a triple bond with the other ...

  4. Atomicity (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Atomicity_(chemistry)

    Atomicity is the total number of atoms present in a molecule of an element. For example, each molecule of oxygen (O 2) is composed of two oxygen atoms.Therefore, the atomicity of oxygen is 2.

  5. Praseodymium (III,IV) oxide - Wikipedia

    en.wikipedia.org/wiki/Praseodymium(III,IV)_Oxide

    Pr 6 O 11 adopts a cubic fluorite crystal structure, measured by XRD, TEM and SEM methods. [3] [5] It can be considered an oxygen deficient form of praseodymium(IV) oxide (PrO 2), with the Pr ions being in a mixed valency state Pr(III) and Pr(IV). [5] This characteristic is what gives the oxide its many useful properties for its catalytic activity.

  6. Pauling's rules - Wikipedia

    en.wikipedia.org/wiki/Pauling's_rules

    One of Pauling's examples is olivine, M 2 SiO 4, where M is a mixture of Mg 2+ at some sites and Fe 2+ at others. The structure contains distinct SiO 4 tetrahedra which do not share any oxygens (at corners, edges or faces) with each other. The lower-valence Mg 2+ and Fe 2+ cations are surrounded by polyhedra which do share oxygens.

  7. Equivalent weight - Wikipedia

    en.wikipedia.org/wiki/Equivalent_weight

    In chemistry, equivalent weight (also known as gram equivalent [1] or equivalent mass) is the mass of one equivalent, that is the mass of a given substance which will combine with or displace a fixed quantity of another substance.

  8. Mixed-valence complex - Wikipedia

    en.wikipedia.org/wiki/Mixed-valence_complex

    [Ru 2 (OAc) 4 Cl] n is a coordination polymer that is also mixed-valence (Ru(II)Ru(III)). Mixed-valence compounds are subdivided into three groups, according to the Robin–Day classification: [3] Class I, where the valences are trapped—localized on a single site—such as Pb 3 O 4 and antimony tetroxide. There are distinct sites with ...

  9. Equivalent concentration - Wikipedia

    en.wikipedia.org/wiki/Equivalent_concentration

    For example, sulfuric acid (H 2 SO 4) is a diprotic acid. Since only 0.5 mol of H 2 SO 4 are needed to neutralize 1 mol of OH −, the equivalence factor is: f eq (H 2 SO 4) = 0.5. If the concentration of a sulfuric acid solution is c(H 2 SO 4) = 1 mol/L, then its normality is 2 N. It can also be called a "2 normal" solution.