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  2. Reactions of organocopper reagents - Wikipedia

    en.wikipedia.org/wiki/Reactions_of_organocopper...

    Cyanocuprates undergo S N 2' substitution in the presence of allyl electrophiles and conjugate addition reactions in the presence of enones. Higher-order cyanocuprates (R 2 Cu(CN)Li 2) are formed upon the reaction of two equivalents of organolithium with copper(I) cyanide. These reagents are more reactive towards substitution than the ...

  3. List of copper alloys - Wikipedia

    en.wikipedia.org/wiki/List_of_copper_alloys

    The content of aluminium ranges mostly between 5% and 11%. Iron, nickel, manganese and silicon are sometimes added. They have higher strength and corrosion resistance than other bronzes, especially in marine environment, and have low reactivity to sulphur compounds.

  4. Mass concentration (chemistry) - Wikipedia

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

    In chemistry, the mass concentration ρ i (or γ i) is defined as the mass of a constituent m i divided by the volume of the mixture V. [1]= For a pure chemical the mass concentration equals its density (mass divided by volume); thus the mass concentration of a component in a mixture can be called the density of a component in a mixture.

  5. IB Group 4 subjects - Wikipedia

    en.wikipedia.org/wiki/IB_Group_4_subjects

    Paper 2 – free response questions on the SSC (32% at SL, 36% at HL) Paper 3 – free response questions on the options (24% at SL, 20% at HL) At the Standard Level, the examinations are respectively 45 minutes, 1 hour and 15 minutes, and 1 hour long. At the Higher Level, they are 1 hour, 2 hours and 15 minutes, and 1 hour and 15 minutes long.

  6. Rotamer - Wikipedia

    en.wikipedia.org/wiki/Rotamer

    The ring-flip proceeds at a rates of approximately 10 5 ring-flips/sec, with an overall energy barrier of 10 kcal/mol (42 kJ/mol). This barrier precludes separation at ambient temperatures. [ 22 ] However, at low temperatures below the coalescence point one can directly monitor the equilibrium by NMR spectroscopy and by dynamic, temperature ...

  7. Precipitation (chemistry) - Wikipedia

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

    [1] [2] The solid formed is called the precipitate. [3] In case of an inorganic chemical reaction leading to precipitation, the chemical reagent causing the solid to form is called the precipitant. [4] The clear liquid remaining above the precipitated or the centrifuged solid phase is also called the supernate or supernatant.

  8. Activated complex - Wikipedia

    en.wikipedia.org/wiki/Activated_complex

    In chemistry, an activated complex represents a collection of intermediate structures in a chemical reaction when bonds are breaking and forming. The activated complex is an arrangement of atoms in an arbitrary region near the saddle point of a potential energy surface . [ 1 ]

  9. Cahn–Ingold–Prelog priority rules - Wikipedia

    en.wikipedia.org/wiki/Cahn–Ingold–Prelog...

    Compare the atomic number (Z) of the atoms directly attached to the stereocenter; the group having the atom of higher atomic number Z receives higher priority (i.e. number 1). If there is a tie, the atoms at distance 2 from the stereocenter have to be considered: a list is made for each group of further atoms bonded to the one directly attached ...