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  2. Chemical polarity - Wikipedia

    en.wikipedia.org/wiki/Chemical_polarity

    Chemical polarity. A water molecule, a commonly used example of polarity. Two charges are present with a negative charge in the middle (red shade), and a positive charge at the ends (blue shade). In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a ...

  3. VSEPR theory - Wikipedia

    en.wikipedia.org/wiki/VSEPR_theory

    The bond angle for water is 104.5°. Valence shell electron pair repulsion (VSEPR) theory (/ ˈvɛspər, vəˈsɛpər / VESP-ər, [1]: 410 və-SEP-ər[2]) is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. [3] It is also named the Gillespie-Nyholm ...

  4. Chemical bond - Wikipedia

    en.wikipedia.org/wiki/Chemical_bond

    Molecules that are formed primarily from non-polar covalent bonds are often immiscible in water or other polar solvents, but much more soluble in non-polar solvents such as hexane. A polar covalent bond is a covalent bond with a significant ionic character. This means that the two shared electrons are closer to one of the atoms than the other ...

  5. Hydrophobic effect - Wikipedia

    en.wikipedia.org/wiki/Hydrophobic_effect

    The hydrophobic effect is the observed tendency of nonpolar substances to aggregate in an aqueous solution and to be excluded by water. [1][2] The word hydrophobic literally means "water-fearing", and it describes the segregation of water and nonpolar substances, which maximizes the entropy of water and minimizes the area of contact between ...

  6. Chemical structure - Wikipedia

    en.wikipedia.org/wiki/Chemical_structure

    Chemical structure. A chemical structure of a molecule is a spatial arrangement of its atoms and their chemical bonds. Its determination includes a chemist 's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target molecule or other solid. Molecular geometry refers to the spatial arrangement of ...

  7. Hydrophobe - Wikipedia

    en.wikipedia.org/wiki/Hydrophobe

    Hydrophobe. 165° water contact angle on a surface modified using plasma technology system surface chemistry. The contact angle is the red angle plus 90°. In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (called a hydrophobe). [1] In contrast, hydrophiles are attracted to water.

  8. Non-random two-liquid model - Wikipedia

    en.wikipedia.org/wiki/Non-random_two-liquid_model

    The non-random two-liquid model[1] (abbreviated NRTL model) is an activity coefficient model introduced by Renon and Prausnitz in 1968 that correlates the activity coefficients of a compound with its mole fractions in the liquid phase concerned. It is frequently applied in the field of chemical engineering to calculate phase equilibria.

  9. Simple random sample - Wikipedia

    en.wikipedia.org/wiki/Simple_random_sample

    In statistics, a simple random sample (or SRS) is a subset of individuals (a sample) chosen from a larger set (a population) in which a subset of individuals are chosen randomly, all with the same probability. It is a process of selecting a sample in a random way. In SRS, each subset of k individuals has the same probability of being chosen for ...