enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Nitrate test - Wikipedia

    en.wikipedia.org/wiki/Nitrate_test

    A common nitrate test, known as the brown ring test [2] can be performed by adding iron(II) sulfate to a solution of a nitrate, then slowly adding concentrated sulfuric acid such that the acid forms a layer below the aqueous solution. A brown ring will form at the junction of the two layers, indicating the presence of the nitrate ion. [3]

  3. GCSE - Wikipedia

    en.wikipedia.org/wiki/GCSE

    The General Certificate of Secondary Education (GCSE) is an academic qualification in a range of subjects taken in England, Wales, and Northern Ireland, having been introduced in September 1986 and its first exams taken in 1988.

  4. BBC Bitesize - Wikipedia

    en.wikipedia.org/wiki/BBC_Bitesize

    GCSE Bitesize was launched in January 1998, covering seven subjects. For each subject, a one- or two-hour long TV programme would be broadcast overnight in the BBC Learning Zone block, and supporting material was available in books and on the BBC website. At the time, only around 9% of UK households had access to the internet at home.

  5. Salt (chemistry) - Wikipedia

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

    The constituent ions are held together by electrostatic forces termed ionic bonds. The component ions in a salt can be either inorganic, such as chloride (Cl −), or organic, such as acetate (CH 3 COO −). Each ion can be either monatomic (termed simple ion), such as sodium (Na +) and chloride (Cl −) in sodium chloride, or polyatomic, such ...

  6. Griess test - Wikipedia

    en.wikipedia.org/wiki/Griess_test

    The Griess test is an analytical chemistry test which detects the presence of nitrite ion in solution. One of its most important uses is the determination of nitrite in drinking water . The Griess diazotization reaction, on which the Griess reagent relies, was first described in 1858 by Peter Griess .

  7. Ion - Wikipedia

    en.wikipedia.org/wiki/Ion

    Forming an ionic bond, Li and F become Li + and F − ions. An ion (/ ˈ aɪ. ɒ n,-ən /) [1] is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge ...

  8. Phosphate test - Wikipedia

    en.wikipedia.org/wiki/Phosphate_test

    A simple qualitative method to determine the presence of phosphate ions in a sample is as follows. A small amount of the sample is acidified with concentrated nitric acid, to which a little ammonium molybdate is added. The presence of phosphate ions is indicated by the formation of a bright yellow precipitate layer of ammonium phosphomolybdate ...

  9. Counterion - Wikipedia

    en.wikipedia.org/wiki/Counterion

    In chemistry, a counterion (sometimes written as "counter ion", pronounced as such) is the ion that accompanies an ionic species in order to maintain electric neutrality. In table salt (NaCl, also known as sodium chloride) the sodium ion (positively charged) is the counterion for the chloride ion (negatively charged) and vice versa.