Ch. 13 Solutions What 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 cream Heterogenous mixture – can distinguish the substances in the mixture. Ex. Stew, salad, chocolate chip ice cream Video

What is an electrolyte? A substance that conducts electricity in a solution. Ex. NaCl in water A 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)

Factors that affect the rate of dissolving 1. Heat the solvent 2. Stir/mix the solution 3. Crush/grind the solution What 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. HCl A 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)

Molarity Molarity 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

Molality Molality 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