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Trisodium phosphate (TSP) is an inorganic compound with the chemical formula Na 3 P O 4.It is a white, granular or crystalline solid, highly soluble in water, producing an alkaline solution.
The degree of dissociation in gases is denoted by the symbol α, where α refers to the percentage of gas molecules which dissociate. Various relationships between K p and α exist depending on the stoichiometry of the equation. The example of dinitrogen tetroxide (N 2 O 4) dissociating to nitrogen dioxide (NO 2) will be taken.
Branched polyphosphoric acids give similarly branched polyphosphate anions. The simplest example of this is triphosphono phosphate [OP(OPO 3) 3] 9− and its partially dissociated versions. The general formula for such (non-cyclic) polyphosphate anions, linear or branched, is [H n+2−k P n O 3n+1] k−, where the charge k may vary from 1 to n + 2.
With specific values for C a and K a this quadratic equation can be solved for x. Assuming [4] that pH = −log 10 [H +] the pH can be calculated as pH = −log 10 x. If the degree of dissociation is quite small, C a ≫ x and the expression simplifies to = and pH = 1 / 2 (pK a − log C a).
The degree of dissociation is the fraction of the original solute molecules that have dissociated. It is usually indicated by the Greek symbol α {\displaystyle \alpha } . There is a simple relationship between this parameter and the van 't Hoff factor.
The molar ionic strength, I, of a solution is a function of the concentration of all ions present in that solution. [3]= = where one half is because we are including both cations and anions, c i is the molar concentration of ion i (M, mol/L), z i is the charge number of that ion, and the sum is taken over all ions in the solution.
A solubility equilibrium exists when a chemical compound in the solid state is in chemical equilibrium with a solution containing the compound. This type of equilibrium is an example of dynamic equilibrium in that some individual molecules migrate between the solid and solution phases such that the rates of dissolution and precipitation are equal to one another.
[c] [2] For example, a hypothetical weak acid having K a = 10 −5, the value of log K a is the exponent (−5), giving pK a = 5. For acetic acid, K a = 1.8 x 10 −5, so pK a is 4.7. A higher K a corresponds to a stronger acid (an acid that is more dissociated at equilibrium).