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. Miscibility - Wikipedia

    en.wikipedia.org/wiki/Miscibility

    An example in liquids is the miscibility of water and ethanol as they mix in all proportions. [1] By contrast, substances are said to be immiscible if the mixture does not form a solution for certain proportions. For one example, oil is not soluble in water, so these two solvents are immiscible

  4. Mixture - Wikipedia

    en.wikipedia.org/wiki/Mixture

    In chemistry, a mixture is a material made up of two or more different chemical substances which can be separated by physical method. It is an impure substance made up of 2 or more elements or compounds mechanically mixed together in any proportion. [ 1 ]

  5. Physical change - Wikipedia

    en.wikipedia.org/wiki/Physical_change

    However mixtures can have different properties from the individual components. One familiar example is the mixture of fine sand with water used to make sandcastles. Neither the sand on its own nor the water on its own will make a sand-castle but by using physical properties of surface tension, the mixture behaves in a different way.

  6. Powder mixture - Wikipedia

    en.wikipedia.org/wiki/Powder_mixture

    A random mixture can be obtained if two different free-flowing powders of approximately the same particle size, density and shape are mixed (see figure A). [3] Only primary particles are present in this type of mixture, i.e., the particles are not cohesive and do not cling to one another. The mixing time will determine the quality of the random ...

  7. Suspension (chemistry) - Wikipedia

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

    In chemistry, a suspension is a heterogeneous mixture of a fluid that contains solid particles sufficiently large for sedimentation. The particles may be visible to the naked eye, usually must be larger than one micrometer, and will eventually settle, although the mixture is only classified as a suspension when and while the particles have not ...

  8. List of alchemical substances - Wikipedia

    en.wikipedia.org/wiki/List_of_alchemical_substances

    Purple of Cassius – formed by precipitating a mixture of gold, stannous and stannic chlorides, with alkali. Used for glass coloring; Realgar – arsenic disulfide, an ore of arsenic. Regulus of antimony; Resin of copper – copper(I) chloride (cuprous chloride), formed by heating copper with corrosive sublimate.

  9. Chemical equilibrium - Wikipedia

    en.wikipedia.org/wiki/Chemical_equilibrium

    For example, a mixture of SO 2 and O 2 is metastable as there is a kinetic barrier to formation of the product, SO 3. 2 SO 2 + O 2 ⇌ 2 SO 3. The barrier can be overcome when a catalyst is also present in the mixture as in the contact process, but the catalyst does not affect the equilibrium concentrations.