TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

A measurement of the completeness of an incomplete chemical reaction. It is defined as the negative logarithm(to the base 10) of the equilibrium constant, K, for the reaction in question. The pK is most frequently used to express the extent of dissociation or the strength of weak acids... In a solution of weak acid, if the concentration of undissociated acid is equal to the concentration of the anion of the acid, the pK will be equal to the pH.  1, record 1, English, - pK

Record number: 1, Textual support number: 1 OBS

ionisation behavior: term extracted from the “Glossaire de l’environnement” and reproduced with permission of the Organisation for Economic Co-operation and Development.  3, record 1, English, - pK

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 DEF

Expression signifiant -log K avec K = A x B sur AB expression de la loi d'action de masses pour la dissociation d'une molécule AB. Si le corps (acide sulfurique) subit deux dissociations successives, on trouvera des expressions notées pK₁ et pK₂.  1, record 1, French, - pK

Record number: 1, Textual support number: 1 OBS

On dit "pK", tout comme on dit "pH"; contrairement au pH, cependant, qui est le symbole du potentiel hydrogène, le symbole "pK" ne renvoit à aucun terme de référence.  3, record 1, French, - pK

Record number: 1, Textual support number: 2 OBS

comportement d'ionisation : terme extrait du «Glossaire de l’environnement» et reproduit avec l’autorisation de l’Organisation de coopération et de développement économiques.  4, record 1, French, - pK

Record 1,  Textual support,  Spanish

Record 2,  Textual support,  English

Record number: 2, Textual support number: 1 DEF

A dissociation reaction of the ammonia molecule producing H+ and NH₂-species.  2, record 2, English, - ammonolysis

Record 2,  Textual support,  French

Record 2,  Textual support,  Spanish

Record 3,  Textual support,  English

Record number: 3, Textual support number: 1 CONT

... Calcium and Magnesium react with other chemicals in the water. The warm water acts as a catalyst and increases the number of reactions depending on the concentration of calcium and magnesium. The reaction which takes place is the dissociation of calcium hydrocarbonate, formula : Ca(HC0₃) and magnesium hydrocarbonate, formula : Mg(HC0[ susbcript 3]) ₂. Both of these are soluble solids, which means they can dissolve when put in water. When these two soluble salts dissociate, they form carbon dioxide(a gas), which is released from the water, and calcium and magnesium carbonate. These two compounds are not soluble and are therefore taken out of solution. And it is these substances that cause the filmy, fuzzy crud on the glass of your aquarium when the water evaporates.  3, record 3, English, - magnesium%20bis%28hydrogencarbonate%29

Record number: 3, Textual support number: 2 CONT

San Marcos River Basin. The lithology and the water flow conditions are the major factors that determine the chemical composition of the waters and the hydrogeochemical patterns. We can distinguish the following water types: sodium calcium hydrocarbonate for waters from the sedimentary-effusive rocks, magnesium hydrocarbonate for the waters which originate in the ultrabasic massif, and calcium hydrocarbonate for that waters which flow in the karst areas (at the source, caves, exsurgences and springs from the saturation zone).  4, record 3, English, - magnesium%20bis%28hydrogencarbonate%29

Record number: 3, Textual support number: 1 OBS

magnesium hydrocarbonate: traditional name, to be avoided.  1, record 3, English, - magnesium%20bis%28hydrogencarbonate%29

Record number: 3, Textual support number: 2 OBS

Chemical formula: Mg(HCO₃)₂  5, record 3, English, - magnesium%20bis%28hydrogencarbonate%29

Record 3,  Textual support,  French

Record number: 3, Textual support number: 1 CONT

(Matériel pour le grimpeur) sac à pof : petit sac dans lequel le grimpeur met du pof (poudre de résine ) ou de la magnésie (hydrocarbonate de magnésium) afin d'absorber la transpiration des mains et d'éviter que celle-ci le fasse glisser.  4, record 3, French, - bis%28hydrog%C3%A9nocarbonate%29%20de%20magn%C3%A9sium

Record number: 3, Textual support number: 1 OBS

hydrocarbonate de magnésium : nom traditionnel, à éviter.  1, record 3, French, - bis%28hydrog%C3%A9nocarbonate%29%20de%20magn%C3%A9sium

Record number: 3, Textual support number: 2 OBS

Formule chimique : Mg(HCO₃)₂  5, record 3, French, - bis%28hydrog%C3%A9nocarbonate%29%20de%20magn%C3%A9sium

Record 3,  Textual support,  Spanish

Record 4,  Textual support,  English

Record number: 4, Textual support number: 1 DEF

An acid with a high degree of dissociation in solution, for example, mineral acids, such as hydrochloric acid, HC1, sulfuric acid, H₂SO₄, or nitric acid, HNO₃.  2, record 4, English, - strong%20acid

Record number: 4, Textual support number: 1 CONT

The ionisation of an acid in water can be written as HA=H+-A-. Qualitatively, an acid is strong if this reaction goes extensively toward the ionic products and weak if the ionisation is only slight.... [The] dissociation constant is a large number for a strong acid and a small number for a weak acid.  3, record 4, English, - strong%20acid

Record 4,  Textual support,  French

Record number: 4, Textual support number: 1 DEF

Acide complètement dissocié en ions [...]  2, record 4, French, - acide%20fort

Record number: 4, Textual support number: 1 CONT

Qualitativement, un acide est d'autant plus fort que cette réaction [ionisation] se déplace vers les ions, et, inversement, d'autant plus faible que l'ionisation est plus petite. Quantitativement [...], à 25°C dans l'eau, la valeur K_a est de 1,754 x 10^-5 pour l'acide acétique (acide faible), tandis qu'elle est de 1,6 x 10^-1 pour l'acide picrique (acide assez fort).  3, record 4, French, - acide%20fort

Record 4,  Textual support,  Spanish

Record number: 4, Textual support number: 1 DEF

Acido que presenta un elevado grado de disociación cuando se encuentra en disolución.  1, record 4, Spanish, - %C3%A1cido%20fuerte

Record 5,  Textual support,  English

Record number: 5, Textual support number: 1 DEF

An acid that does not ionize greatly; for example, acetic acid or carbonic acid.  2, record 5, English, - weak%20acid

Record number: 5, Textual support number: 1 CONT

The ionisation of an acid in water can be written as HA=H+-A-. Qualitatively, an acid is strong if this reaction goes extensively toward the ionic products and weak if the ionisation is only slight.... [The] dissociation constant is a large number for a strong acid and a small number for a weak acid.  3, record 5, English, - weak%20acid

Record 5,  Textual support,  French

Record number: 5, Textual support number: 1 DEF

Acide peu dissocié.  2, record 5, French, - acide%20faible

Record number: 5, Textual support number: 1 CONT

Qualitativement, un acide est d'autant plus fort que cette réaction [ionisation] se déplace vers les ions, et inversement, d'autant plus faible que l'ionisation est plus petite. Quantitativement [...], à 25°C dans l'eau, la valeur K_a est de 1,754 x 10^-5 pour l'acide acétique (acide faible), tandis qu'elle est de 1,6 x 10^-1 pour l'acide picrique (acide assez fort).  1, record 5, French, - acide%20faible

Record 5,  Textual support,  Spanish

Record 6,  Textual support,  English

Record number: 6, Textual support number: 1 DEF

The equilibrium dissociation constant of the reaction EI=E + I, where E is the enzyme and I is the inhibitor.  1, record 6, English, - inhibitor%20constant

Record number: 6, Textual support number: 1 CONT

The inhibitor constant K_i is comparable to K_s, the dissociation constant of the enzyme-substrate complex.  2, record 6, English, - inhibitor%20constant

Record number: 6, Textual support number: 1 OBS

K_i, symbol for inhibitor constant.  3, record 6, English, - inhibitor%20constant

Record 6,  Textual support,  French

Record number: 6, Textual support number: 1 DEF

Constante de dissociation du complexe enzyme-inhibiteur. Elle est ainsi comparable à K_s constante de dissociation du complexe enzyme-substrat.  1, record 6, French, - constante%20d%27inhibiteur

Record number: 6, Textual support number: 1 CONT

Les exemples d'inhibiteurs compétitifs sont nombreux. Le cas de la succinate-déshydrogénase, enzyme du cycle tricarboxylique de Krebs, est particulièrement démonstratif. La succinate-déshydrogénase a pour substrat l'acide succinique. (...) Un analogue structural de l'acide succinique, l'acide malonique, est un inhibiteur compétitif de l'enzyme. Le K_m pour succinate est égal à 1,4.10-³M. Le K_i pour l'inhibiteur malonate est égal à 0,04.10-³M.  3, record 6, French, - constante%20d%27inhibiteur

Record number: 6, Textual support number: 1 OBS

K_i est un symbole utilisé pour désigner la constante d'inhibition.  2, record 6, French, - constante%20d%27inhibiteur

Record number: 6, Textual support number: 2 OBS

Le terme Ki s'écrit K_i  4, record 6, French, - constante%20d%27inhibiteur

Record 6,  Textual support,  Spanish

Record 7,  Textual support,  English

Record number: 7, Textual support number: 1 CONT

Sulphur species in solution eventually reach equilibrium with the ambient SO₂ concentration(further uptake is much diminished and is dependent on the removal of S(IV) from solution usually by oxidation to S(VI)(sulphate), a reaction that generates acidity). In solution SO₂(aq) establishes an equilibrium among the S(IV) species SO₃^2-, HSO₃[superscript-] and SO₂. H₂O, the concentration of a particular dissociation product depending on pH of the medium.  1, record 7, English, - S%28IV%29species

Record 7,  Textual support,  French

Record number: 7, Textual support number: 1 CONT

Les espèces sulfureuses en solution atteignent finalement un équilibre avec la concentration ambiante de SO₂ (une nouvelle absorption est fort réduite et dépend de l'élimination du S(IV) de la solution, habituellement par oxydation, d'où la formation de S(VI) (sulfate), une réaction qui engendre l'acidité). En solution, SO₂ (aq) réalise un équilibre parmi les espèces S(IV), soit SO^2-, HSO₃- et SO2.H2O, la concentration d'un produit particulier de dissociation dépendant du pH du milieu.  1, record 7, French, - esp%C3%A8ce%20S%28IV%29

Record 7,  Textual support,  Spanish

Record 8,  Textual support,  English

Record 8,  Textual support,  French

Record number: 8, Textual support number: 1 DEF

Réaction chimique qui provoque une décomposition réversible et non électrolytique d'une molécule.  1, record 8, French, - r%C3%A9action%20de%20dissociation

Record 8,  Textual support,  Spanish