A packet of granulated sugar would dissolve faster than a cube of sugar. The rate of dissolution would be increased by stirring, or agitating the solution. Finally, the sugar would dissolve faster in hot tea than it would in cold tea. The rate at which a solute dissolves depends upon the size of the solute particles. Dissolution is a surface phenomenon, since it depends on solvent molecules colliding with the outer surface of the solute.
A given quantity of solute dissolves faster when it is ground into small particles, rather than in the form of large pieces, because more surface area is exposed. A packet of granulated sugar exposes far more surface area to the solvent and dissolves more quickly than a sugar cube.
The solubility chart shows the solubility of many salts. Salts of alkali metals and ammonium , as well as those of nitrate and acetate, are always soluble. Carbonates, hydroxides, sulfates, phosphates, and heavy metal salts are often insoluble. Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:. Skip to main content. Aqueous Reactions.
As the temperature of a solution is increased, the average kinetic energy of the molecules that make up the solution also increases. This increase in kinetic energy allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions. The average kinetic energy of the solute molecules also increases with temperature, and it destabilizes the solid state.
The increased vibration kinetic energy of the solute molecules causes them to be less able to hold together, and thus they dissolve more readily. A useful application of solubility is recrystallizaton. During recrystallization, an impure substance is taken up in a volume of solvent at a temperature at which it is insoluble, which is then heated until it becomes soluble. The impurities dissolve as well, but when the solution is cooled, it is often possible to selectively crystallize, or precipitate, the desired substance in a purer form.
Solubility of a gas in water tends to decrease with increasing temperature, and solubility of a gas in an organic solvent tends to increase with increasing temperature. Several factors affect the solubility of gases: one of these factors is temperature. In general, solubility of a gas in water will decrease with increasing temperature: colder water will be able to have more gas dissolved in it.
Solubilities of Gases in Water : Methane, oxygen, carbon monoxide, nitrogen, and helium all have different solubilities in water, but all of them become less soluble with increasing temperature. When the temperature of a river, lake, or stream is raised abnormally high, usually due to the discharge of hot water from some industrial process, the solubility of oxygen in the water is decreased.
In severe cases, temperature changes can result in large-scale fish kills. The trend that gas solubility decreases with increasing temperature does not hold in all cases. Definition the number of moles of solute dissolved in one liter of solution.
Term What are three colligative properties of solution? Definition three important colligative properties of solution are vapor-pressure lowering, boiling-point elevation, and freezing-point depression. Term What factor determines the amount by which a solution's vapor pressure, freezing point, and boiling point differ from those properties of the solvent? Definition The decrease in a solution's vapor pressure is proportional to the number of particles the solute makes in solution.
Term Colligative property. Definition a property that depends only upon the number of solute particles, and not upon their identity. Term Freezing-point depression. Definition the difference in temperature between the freezing point of a solution and the freezing point of the pure solvent.
Term Boiling-point elevation. Definition the difference in temperature between the boiling point of a solution and the noiling point of the pure solvent. Term What are two ways of expressing the concentration of a solution? Definition the unit molality and mole fractions are two additional ways in which chemists express the concentration of a solution.
Term How are freezing-point depression and boiling-point elevation related to molality? Definition the magnitudes of the freezing-point depression delta Tf and the boiling-point elevation delta Tb of a solution are directly proportional to the molal concentration m , when the solute is molecular, not ionic.
Term Molality m. Definition the number of moles of solute dissolved in 1 kilogram g of solvent.
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