enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Calculator input methods - Wikipedia

    en.wikipedia.org/wiki/Calculator_input_methods

    On a single-step or immediate-execution calculator, the user presses a key for each operation, calculating all the intermediate results, before the final value is shown. [1] [2] [3] On an expression or formula calculator, one types in an expression and then presses a key, such as "=" or "Enter", to evaluate the expression.

  3. Pensky–Martens closed-cup test - Wikipedia

    en.wikipedia.org/wiki/Pensky–Martens_closed-cup...

    A brass test cup is filled with a test specimen and closed with a lid, through which an ignition source can be introduced periodically. The sample is heated and stirred at specified rates depending on the material that is being tested.

  4. Chemical test - Wikipedia

    en.wikipedia.org/wiki/Chemical_test

    The Schiff test detects aldehydes; Tollens' reagent tests for aldehydes (known as the silver mirror test) The Zeisel determination tests for the presence of esters or ethers; Lucas' reagent is used to distinguish between primary, secondary and tertiary alcohols. The bromine test is used to test for the presence of unsaturation and phenols.

  5. Donor number - Wikipedia

    en.wikipedia.org/wiki/Donor_number

    In chemistry a donor number (DN) is a quantitative measure of Lewis basicity.A donor number is defined as the negative enthalpy value for the 1:1 adduct formation between a Lewis base and the standard Lewis acid SbCl 5 (antimony pentachloride), in dilute solution in the noncoordinating solvent 1,2-dichloroethane with a zero DN.

  6. Viscosity index - Wikipedia

    en.wikipedia.org/wiki/Viscosity_index

    [1] The viscosity of a lubricant is closely related to its ability to reduce friction in solid body contacts. Generally, the least viscous lubricant which still forces the two moving surfaces apart to achieve " fluid bearing " conditions is desired.

  7. Chemical specificity - Wikipedia

    en.wikipedia.org/wiki/Chemical_specificity

    Chemical specificity is the ability of binding site of a macromolecule (such as a protein) to bind specific ligands. The fewer ligands a protein can bind, the greater its specificity. Specificity describes the strength of binding between a given protein and ligand.

  8. Qualitative inorganic analysis - Wikipedia

    en.wikipedia.org/wiki/Qualitative_inorganic_analysis

    The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes. [ 1 ] [ 2 ] Qualitative inorganic analysis is that branch or method of analytical chemistry which seeks to establish the elemental composition of inorganic compounds ...

  9. Scientific calculator - Wikipedia

    en.wikipedia.org/wiki/Scientific_calculator

    The HP-35, introduced on February 1, 1972, was Hewlett-Packard's first pocket calculator and the world's first handheld scientific calculator. [7] Like some of HP's desktop calculators it used RPN. Introduced at US$395, the HP-35 was available from 1972 to 1975. Texas Instruments (TI), after the production of several units with scientific ...