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where ω is the mass fraction of the dissolved substance;
m d. subs. - the dissolved substance mass, g;
m solution - the solution mass, g.
The mass fraction of the dissolved substance ω is expressed in parts per unit or per
cent.
2) molar concentration Сm (molarity) of the solution - is the ratio of the
amount of dissolved substance to the volume of a solution:
3
Units of measurement are Сm - mol/dm .
The hydrogen pH is a negative decimal logarithm of Hydrogen ions
concentration.
+
рН = - lg [Н ]
acid solutions: рН < 7
neutral solutions: рН = 7
alkaline solutions: рН > 7
Similarly to the hydrogen index the concept of the hydroxyl ion index is
introduced:
–
рОН = – lg [OН ].
Then at a temperature of 298 K the equation is correct:
рН + рОН = 14
8.3 Salts hydrolysis
Hydrolysis is a chemical interaction of salts with slightly dissociated water
molecules, which leads to the formation of even weaker electrolytes. This reaction
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