enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. List of unsolved problems in chemistry - Wikipedia

    en.wikipedia.org/wiki/List_of_unsolved_problems...

    Protein folding problem: Is it possible to predict the secondary, tertiary and quaternary structure of a polypeptide sequence based solely on the sequence and environmental information? Inverse protein-folding problem: Is it possible to design a polypeptide sequence which will adopt a given structure under certain environmental conditions?

  3. Kohn–Sham equations - Wikipedia

    en.wikipedia.org/wiki/Kohn–Sham_equations

    In physics and quantum chemistry, specifically density functional theory, the Kohn–Sham equation is the non-interacting Schrödinger equation (more clearly, Schrödinger-like equation) of a fictitious system (the "Kohn–Sham system") of non-interacting particles (typically electrons) that generate the same density as any given system of interacting particles.

  4. Cubic equations of state - Wikipedia

    en.wikipedia.org/wiki/Cubic_equations_of_state

    = 2 for water. = degree of polymerization for polyvinylphenol. So you use the density and temperature to calculate then use to calculate the other quantities. Technically, the ESD equation is no longer cubic when the association term is included, but no artifacts are introduced so there are only three roots in density.

  5. Graham's law - Wikipedia

    en.wikipedia.org/wiki/Graham's_law

    M 2 is the molar mass of gas 2. Graham's law states that the rate of diffusion or of effusion of a gas is inversely proportional to the square root of its molecular weight. Thus, if the molecular weight of one gas is four times that of another, it would diffuse through a porous plug or escape through a small pinhole in a vessel at half the rate ...

  6. Boyle's law - Wikipedia

    en.wikipedia.org/wiki/Boyle's_law

    where P is the pressure of the gas, V is the volume of the gas, and k is a constant for a particular temperature and amount of gas.. Boyle's law states that when the temperature of a given mass of confined gas is constant, the product of its pressure and volume is also constant.

  7. Density - Wikipedia

    en.wikipedia.org/wiki/Density

    To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative density" or "specific gravity", i.e. the ratio of the density of the material to that of a standard material, usually water. Thus a relative density less than one relative to water means that the substance ...

  8. Relative density - Wikipedia

    en.wikipedia.org/wiki/Relative_density

    Relative density can be calculated directly by measuring the density of a sample and dividing it by the (known) density of the reference substance. The density of the sample is simply its mass divided by its volume. Although mass is easy to measure, the volume of an irregularly shaped sample can be more difficult to ascertain.

  9. Separation process - Wikipedia

    en.wikipedia.org/wiki/Separation_process

    Analytical chemistry – Study of the separation, identification, and quantification of matter; Chemical process – A method or means of somehow changing one or more chemicals or chemical compounds. High-performance liquid chromatography – Technique in analytical chemistry; Unit operation – Basic step in a process