homogeneous solution

Examples of homogeneous solution in the following topics:

• Homogeneous versus Heterogeneous Solution Equilibria

  • The equilibrium constants for homogeneous and heterogeneous solutions need to be calculated differently.
  • The former are called homogenous reactions, and the later are called heterogeneous reactions.
  • A homogeneous equilibrium is one in which all of the reactants and products are present in a single solution (by definition, a homogeneous mixture).
  • Reactions between solutes in liquid solutions belong to one type of homogeneous equilibria.
  • The phases may be any combination of solid, liquid, or gas phases, and solutions.

• Binary Hydrides

  • Hydride complexes are catalysts and catalytic intermediates in a variety of homogeneous and heterogeneous catalytic cycles.
  • Free hydride anions exist only under extreme conditions and are not invoked for homogeneous solutions.

• Kinetics

  • It serves only to provide a homogeneous solution, since the alkyl halide is relatively insoluble in pure water.

• Molality

  • Molality is a property of a solution that indicates the moles of solute per kilogram of solvent.
  • Molality is an intensive property of solutions, and it is calculated as the moles of a solute divided by the kilograms of the solvent.
  • It is easy to calculate molality if we know the mass of solute and solvent in a solution.
  • This is true for all homogeneous solution concentrations, regardless of if we examine a 1.0 L or 10.0 L sample of the same solution.
  • With this information, we can divide the moles of solute by the kg of solvent to find the molality of the solution:

• Solvent Effects

  • If ions are formed from a neutral compound, as when NaCl is dissolved in water, the oppositely charged cations and anions naturally attract each other, so formation of a dispersed homogeneous solution might appear to be energetically unfavorable.
  • To achieve charge separation of ions in solution, two solvent characteristics are particularly important.
  • Although these two inorganic salts have similar standard enthalpies of solution in water, their standard entropies are quite different.
  • The overall entropy change for solution of NaCl is positive, reflecting the increased disorder of ionization, but the entropy change for CaF2 solution is strongly negative thanks to the solvation shell structure required by the resulting ions.
  • These different entropy changes are incorporated in the free energy of solution, which is exergonic for NaCl, but endergonic for CaF2.

• Osmotic Pressure

  • A solution is defined as a homogeneous mixture of both a solute and solvent.
  • Solutions generally have different properties than the solvent and solute molecules that compose them.
  • Some special properties of solutions are dependent solely on the amount of dissolved solute molecules, regardless of what that solute is; these properties are known as colligative properties.
  • If a solution consisting of both solute and solvent molecules is placed on one side of a membrane and pure solvent is placed on the other side, there is a net flow of solvent into the solution side of the membrane.
  • Discuss the effects of a solute on the osmotic pressure of a solution

• Homogeneous Catalysis

  • Homogeneous catalysis is a class of catalysis in which the catalyst occupies the same phase as the reactants.
  • Catalysts can be classified into two types: homogeneous and heterogeneous.
  • Acid catalysis, organometallic catalysis, and enzymatic catalysis are examples of homogeneous catalysis.
  • Most often, homogeneous catalysis involves the introduction of an aqueous phase catalyst into an aqueous solution of reactants.
  • However, unlike with heterogeneous catalysis, the homogeneous catalyst is often irrecoverable after the reaction has run to completion.

• Alloys

  • An alloy is a mixture or metallic solid solution composed of two or more elements.
  • Complete solid solution alloys give single solid phase microstructure.
  • Partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history.
  • Complete solid solution alloys give single solid phase microstructure.
  • Partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history.

• Substances and Mixtures

  • Mixtures take the form of alloys, solutions, suspensions, and colloids.
  • Often separating the components of a homogeneous mixture is more challenging than separating the components of a heterogeneous mixture.
  • Distinguishing between homogeneous and heterogeneous mixtures is a matter of the scale of sampling.
  • In practical terms, if the property of interest is the same regardless of how much of the mixture is taken, the mixture is homogeneous.
  • Mixtures are described as heterogeneous or homogeneous.

• Using Molarity in Calculations of Solutions

  • In chemistry, molar concentration, or molarity, is defined as moles of solute per total liters of solution.
  • What is the molarity of a solution containing 0.32 moles of NaCl in 3.4 liters of solution?
  • Molarity is a measurement of concentration, with units of mol solute per liter solution.
  • Also, molarity is a ratio that describes the moles of solute per liter of solution.
  • Translate between molarity, grams of solute in solution, and volume of solution.