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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. Sodium borohydride is a reducing agent that finds application in papermaking and dye ...
Bases are proton acceptors; a base will receive a hydrogen ion from water, H 2 O, and the remaining H + concentration in the solution determines pH. A weak base will have a higher H + concentration than a stronger base because it is less completely protonated than a stronger base and, therefore, more hydrogen ions remain in its solution.
In this case H 0 and H − are equivalent to pH values determined by the buffer equation or Henderson-Hasselbalch equation. However, an H 0 value of −21 (a 25% solution of SbF 5 in HSO 3 F ) [ 5 ] does not imply a hydrogen ion concentration of 10 21 mol/dm 3 : such a "solution" would have a density more than a hundred times greater than a ...
Sodium borohydride can, under some circumstances, be used for ester reduction, especially with additives. [ 1 ] Forming aldehydes from carboxylic acid derivatives is challenging because weaker reducing agents (NaBH 4 ) are often very slow at reducing esters and carboxylic acids, whereas stronger reducing agents (LiAlH 4 ) immediately reduce the ...
A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. [1] Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical ...
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 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 .
The pH of a simple solution of an acid in water is determined by both and the acid concentration. For weak acid solutions, it depends on the degree of dissociation, which may be determined by an equilibrium calculation. For concentrated solutions of acids, especially strong acids for which pH < 0, the value is a better measure of acidity than ...