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Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, [5] is an inorganic compound with the formula Na B H 4 (sometimes written as Na[BH 4]). It is a white crystalline solid, usually encountered as an aqueous basic solution .
The values below are standard apparent reduction potentials (E°') for electro-biochemical half-reactions measured at 25 °C, 1 atmosphere and a pH of 7 in aqueous solution. [1] [2] The actual physiological potential depends on the ratio of the reduced (Red) and oxidized (Ox) forms according to the Nernst equation and the thermal voltage.
At 25 °C (77 °F), solutions of which the pH is less than 7 are acidic, and solutions of which the pH is greater than 7 are basic. Solutions with a pH of 7 at 25 °C are neutral (i.e. have the same concentration of H + ions as OH − ions, i.e. the same as pure water). The neutral value of the pH depends on the temperature and is lower than 7 ...
Given its greater H + concentration, the formula yields a lower pH value for the weak base. However, pH of bases is usually calculated in terms of the OH − concentration. This is done because the H + concentration is not a part of the reaction, whereas the OH − concentration is. The pOH is defined as:
Sodium borohydride (Na BH 4) Ferrous compounds that contain the Fe 2+ ion, such as iron(II) sulfate; Stannous compounds that contain the Sn 2+ ion, such as tin(II) chloride; Sulfur dioxide (sometimes also used as an oxidizing agent), Sulfite compounds; Dithionates, e.g. Na 2 S 2 O 6; Thiosulfates, e.g. Na 2 S 2 O 3 (mainly in analytical ...
At low pH values, it efficiently reduces aldehydes and ketones. [7] As the pH increases, the reduction rate slows and instead, the imine intermediate becomes preferential for reduction. [ 7 ] For this reason, NaBH 3 CN is an ideal reducing agent for one-pot direct reductive amination reactions that don't isolate the intermediate imine.
The isohydric principle is the phenomenon whereby multiple acid/base pairs in solution will be in equilibrium with one another, tied together by their common reagent: the hydrogen ion and hence, the pH of solution. That is, when several buffers are present together in the same solution, they are all exposed to the same hydrogen ion activity.
Addition (or removal) of CO 2 to a solution does not change its alkalinity, since the net reaction produces the same number of equivalents of positively contributing species (H +) as negative contributing species (HCO − 3 and/or CO 2− 3). Adding CO 2 to the solution lowers its pH, but does not affect alkalinity. At all pH values: CO 2 + H 2 ...