Ch. 13 SolutionsWhat is a solution?
–A homogeneous mixture of 2 or more substances in a single phase.
What is a substance that is capable of being dissolved?–Soluble
What is the substance being dissolved called?–Solute
The substance that dissolves the solute is called what?–Solvent
Homogenous mixture – can’t distinguish the difference in substances–Ex. Tomato juice, pop, vanilla ice
creamHeterogenous mixture – can
distinguish the substances in the mixture.–Ex. Stew, salad, chocolate chip ice
creamVideo
What is an electrolyte?–A substance that conducts electricity in a solution.
–Ex. NaCl in waterA nonelectrolyte is a substance
that doesn’t conduct electricity in a solution.–Ex. Sugar in water
What is an alloy?–A solid solution with 2 or more metals mixed together.
–Ex. Cu + Sn = Bronze–Ex. Cu + Zn = Brass–Ex. 50% Au + 50% Cu = 12 karat Au
Video
Suspension – is a heterogeneous mixture of a solvent-like substance with particles that slowly settle out.–Ex. Muddy water (separate by a
filter)–Video
Colloids – have particles that are intermediate in size between those in solutions & suspension. Don’t settle.–Ex. Milk (Tyndall Effect)–Video
Factors that affect the rate of dissolving1. Heat the solvent2. Stir/mix the solution3. Crush/grind the solutionWhat is solubility?
–The rate at which the solvent dissolves the solute at a given temp.
–Video
Solutions What is a saturated solution?
–A solution that can’t take on any more solute and dissolve it.
What is a unsaturated solution?–A solution that can take on more solute.
What is supersaturated solution?–A solution with more solute than a
saturated solution. (over saturated) Video
Polar vs. Nonpolar “Likes dissolve alike”A polar molecule dissolves a polar
molecule.–Ex. Water and salt (both polar)–Ex. Gasoline and benzene (non
polar)–Ex. Water and gasoline don’t mix
Polar & nonpolar
Immiscible are substances that is not soluble in each other.–Ex. Gas & water, oil & water
Miscible are substances that are soluble in each other.–Ex. NaCl & water, gas & benzene
Ethanol & ether both have polar and nonpolar ends on their molecules, thus they are able to dissolve both polar and nonpolar substances.
The solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid. Henry’s Law
Example of Henry’s Law–Gas is released in a carbonated pop bottle when opened because the pressure is less.
What is effervescence?–The rapid escape of a gas from a liquid in which it was dissolved in.
Table 13-4 Solubility vs. Temperature
Concentration of a solution is the measurement of the amount of solute in a given amount of solvent or solution.–Ex. Concentrated O.J. or Conc.
HClA concentration of a solution can
be diluted by adding H2O.
Percent by mass is the number of grams of solute dissolved in 100 g of solution. Sample Problem 13-1–Ex. 10 g of NaOH in 90 g of H2O–10 g of NaOH / 10 g of NaOH + 90 g of H2O X 100%
= 10% NaOH (by mass)
MolarityMolarity is the number of moles of
solute in 1 liter of solution.–To find the molarity of a solution you must know the molar mass of the solute.
Molarity (M) = # of moles of solute / # of liters of solution
Example Problem 13-2
MolalityMolality is the concentration of a
solution expressed in moles of solute per kilogram of solvent.
Molality (m) = # of moles of solute / mass of solvent (kg)
Sample Problem 13-4
Nonvolatile is a substance with little tendency to become a gas under the existing condition.–Ex. A lower freezing point & higher boiling point than water.
Colligative property is a property that depends on the # of solute particles, but is independent of their nature.–Ex. antifreeze