Electro-positive sentence example

  • Those elements which are disengaged at the negative pole are termed electro-positive, or positive, or basylous elements, whilst those disengaged at the positive pole are termed electro-negative, or negative, or chlorous elements.
    0
    0
  • Zinc being more electro-positive even than nickel, all the heavy metals must be removed before its deposition is attempted.
    0
    0
  • A rod of perfectly pure zinc, when immersed in dilute sulphuric acid, is so very slowly attacked that there is no visible evolution of gas; but, if a piece of platinum, copper or other more electro-positive metal be brought into contact with the zinc, it dissolves readily, with evolution of hydrogen and formation of the sulphate.
    0
    0
  • Soluble impurities which are more electro-negative than the metal under treatment must, if present, be removed by a preliminary process, and the voltage and other conditions must be so selected that none of the more electro-positive metals are co-deposited with the metal to be refined.
    0
    0
  • The highly electro-positive character of aluminium is most important.
    0
    0
    Advertisement
  • On the other hand, its electro-positive nature necessitates some care in its utilization.
    0
    0
  • At the same time there is a gradual substitution of other metals for copper in the solution, because although copper plus other (more electro-positive) metals are constantly dissolving at the anode, only copper is deposited at the cathode.
    0
    0
  • In the narrow sense "oxidation" may be regarded as the combination of a substance with oxygen, and conversely, "reduction" as the abstraction of oxygen; in the wider sense oxidation includes not merely the addition of oxygen, but also of other electro-negative elements or groups, or the removal of hydrogen or an electro-positive element or group. In inorganic chemistry oxidation is associated in many cases with an increase in the active valency.
    0
    0
  • Ignoring processes of oxidation or reduction simply brought about by heat or some other form of energy, we may regard an oxidizing agent as a substance having a strong affinity for electro-positive atoms or groups, and a reducing agent as having a strong affinity for electro-negative atoms or groups; in the actual processes the oxidizing agent suffers reduction and the reducing agent oxidation.
    0
    0
  • Newlands in England, that if they are arranged in the order of their atomic weights they fall into groups in which similar chemical and physical properties are repeated at periodic intervals; and in particular he showed that if the atomic weights are plotted as ordinates and the atomic volumes as abscissae, the curve obtained presents a series of maxima and minima, the most electro-positive elements appearing at the peaks of the curve in the order of their atomic weights.
    0
    0
    Advertisement
  • From these and other considerations it is obvious that (I) the electrolyte must be such as will freely dissolve the metal to be refined; (2) the electrolyte must be able to dissolve the major portion of the anode, otherwise the mass of insoluble matter on the outer layer will prevent access of electrolyte to the core, which will thus escape refining; (3) the electrolyte should, if possible, be incapable of dissolving metals more electro-negative than that to be refined; (4) the proportion of soluble electro-positive impurities must not be excessive, or these substances will accumulate too rapidly in the solution and necessitate its frequent purification; (5) the current density must be so adjusted to the strength of the solution and to other conditions that no relatively electro-positive metal is deposited, and that the cathode deposit is physically suitable for subsequent treatment; (6) the current density should be as high as is consistent with the production of a pure and sound deposit, without undue expense of voltage, so that the operation may be rapid and the "turnover" large; (7) the electrolyte should be as good a conductor of electricity as possible, and should not, ordinarily, be altered chemically by exposure to air; and (8) the use of porous partitions should be avoided, as they increase the resistance and usually require frequent renewal.
    0
    0