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Solutions. 12.1 - 2. Types of Solutions. Section12.1. solute. The substance… The substance present in the smaller amount. solvent. The substance which … The substance present in the greater amount. solution. One state of matter evenly distributed throughout another. May occur in….
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Solutions 12.1 - 2
Types of Solutions Section12.1
solute • The substance… • The substance present in the smaller amount
solvent • The substance which … • The substance present in the greater amount
solution • One state of matter evenly distributed throughout another. • May occur in…
miscible • Fluids which… • Example:
immiscible • Fluids which… • Example:
Concept Check 12.1 • Identify the solute (s) and solvent (s) in the following solutions. (p 502) • 80 g of Cr and 5 g of Mo • 39% N2, 41% Ar and the rest O2 • 5 g MgCl2 dissolved in 1000 g of H2O
Solubility and the Solution Process Section 12.2
dynamic equilibrium • When a crystal dissolves, particles are dissolving at the same time particles are returning to the crystalline state. When these two processes occur at the same rate, dynamic equilibrium is reached. • Did you notice this in your investigation?
Solubility • Able to dissolve • The amount that dissolves in a given quantity of water at a given temperature to give a saturated solution. (p 502)
Saturated solution • for a given temperature, solute and amount of solvent, as much of the solute that… • Very specific
Supersaturated solutions • contains more … • Typically achieved by…
Factors in Explaining Solubility • The natural tendency of molecules to mix due to their random motions. (food color in water) • Intermolecular forces. If strong forces exist between the MC of the solvent and MC of the solute separately, but only weak forces exist between the solvent and solute the two will not mix.
Like dissolves like! • Molecules with similar IMF are soluble in one another. (p 505) • Small alcohols are soluble in water because of the OH, but as the MC become larger they become insoluble.
Exercise 12.2 p 506. • Which of the following compounds is likely to be more soluble in water: C4H9OH or C4H9SH? Explain.
Solubility of ionic compounds • Ionic Compounds have markedly different solubilities. • These differences in solubility can be explained in terms of the different energies of attraction between ions in the crystal and between ions and water. (p 506)
ion-dipole force • between the ions and water. This attraction is called hydration. • Smaller ionic radius (& greater charge) = large hydration energy because the electric field is more concentrated.
Lattice energies • Lattice energies fight the energy of hydration. If the crystal has a strong lattice energy, it will not dissolve. • Depends on charge of ions & distance between them.