مولالیته (Molality) یک محلول (m)، برابر است با تعداد مول های ماده حل شده در یک کیلوگرم حلال. مولالیته توسط رابطه زیر محاسبه می شود:
|تعداد مول های حل شده||=مولالیته|
مولالیته یک محلول معین با دما تغییر نمی کند، زیرا محلول بر مبنای جرم اجزای سازنده آن تهیه شده است و تغییر دما، تغییری در وزن نمی دهد. مولالیته یک محلول آبی بسیار رقیق تقریبا برابر با مولاریته محلول است، زیرا 100 گرم آب تقریبا 100 میلی لیتر حجم دارد.
منابع و پیوندها
چارلز مورتیمر ، شیمی عمومی ، جلد اول ، مرکز نشر دانشگاهی ، 1381.
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مولالیته از دید wikipedia.org
In chemistry, the molality, b (or m), of a solution is defined as the amount of substance of solute,nsolute , divided by the mass in kg of the solvent, msolvent (not the mass of the solution). The earliest such definition of the intensive property molality and of its adjectival unit, the now-deprecated molal (formerly, a variant of molar, describing a solution of unit molar concentration), appear to have been coined by G. N. Lewis and M. Randall in their 1923 publication of Thermodynamics and the Free Energies of Chemical Substances. Though the two words are subject to being confused with one another, the molality and molarity of a weak aqueous solution happen to be nearly the same, as one kilogram of water (the solvent) occupies 1 liter of volume at room temperature and the small amount of solute would have little effect on the volume...more
مولالیته از دید cartage.org.lb
An alternative unit of concentration to molarity is molality. The molality of a solute is the number of moles of that solute divided by the weight of the solvent in kilograms. For water solutions, 1 kg of water has a volume close to that of 1 liter, so molality and molarity are similar in dilute aqueous solutions. To figure out the molarity of a solution, simply work out the number of moles of the solute (Probably from the molecular weight) and divide by the weight of the solvent. It's probably the case that you're given a volume of solvent rather than the weight: use the density to convert between the two
molality (M) = moles solute/kg of solution
To convert a volume and a molality of a solution to moles of solute, simply solve the above equation for moles of solute:
moles solute = molality * kg of solution...more
مولالیته از دید chemistry.twu.edu
The concentration of a solution refers to the amount of solute in a given amount of solvent. There are two imprecise terms used in this connection. A dilute solution is one that contains relatively little solute in a large amount of solvent. A concentrated solution contains a relatively large amount of solute in a given amount of solvent. As you can see these terms are rather subjective, however for commercially available solutions, particularly acids, the term concentrated refers to the maximum concentration available. There are many ways to express, quantatively, the concentration of a solution. We have already noted that molarity is perhaps the most popular unit of concentration with chemists, molarity does have one important flaw however. Its value changes with temperature. If we wish to have a unit of concentration that is independent of temperature, then it must be based on mass not volume. One such unit is molality, which is the number of moles of solute per kilogram of solvent. The molality (m) or molal concentration is the amount of solute, in moles, per kilogram of solvent...more