Chapter 62 Water Colorless, odorless, and tasteless Density of ice < than density of liquid water – Water expands when it freezes – Ice floats on water – Density of liquid water = 1.00 g/mL – Density of ice = g/mL

Chapter 63 Water (cont.) Freezes at 0°C Boils at 100°C at 1.00 atm pressure – Boiling point increases as atmospheric pressure increases Temperature stays constant during a state change Relatively large amounts of energy needed to melt solid or boil liquid

Chapter 64 Water (cont.)

Chapter 65 Structures of the States of Matter

Chapter 66 Solutions Homogeneous mixture of two or more substances Solute – what is being dissolved Solvent – what is doing the dissolving Aqueous solutions – water is solvent

Chapter 67 Solubility Soluble: an appreciable quantity dissolves Insoluble: very little, if any, quantity dissolves Dilute solution: little solute in a lot of water Concentrated solution: lots of solute in the solvent

Chapter 68 Solutions (cont.)

Tro's Introductory Chemistry, Chapter 139 Will It Dissolve In Water? ions are attracted to polar solvents – many ionic compounds dissolve in water polar molecules are attracted to polar solvents – table sugar, ethyl alcohol and glucose all dissolve well in water nonpolar molecules are attracted to nonpolar solvents –  -carotene, (C 40 H 56 ), is not water soluble; it dissolves in fatty (nonpolar) tissues many molecules have both polar and nonpolar structures – whether they will dissolve in water depends on the kind, number and location of polar and nonpolar structural features in the molecule

Tro's Introductory Chemistry, Chapter 1310 Salt Dissolving in Water

Tro's Introductory Chemistry, Chapter 1311 Solvated Ions When materials dissolve, the solvent molecules surround the solvent particles due to the solvent’s attractions for the solute. The process is called solvation. Solvated ions are effectively isolated from each other.

Tro's Introductory Chemistry, Chapter 1312 Solubility there is usually a limit to the solubility of one substance in another – gases are always soluble in each other – two liquids that are mutually soluble are said to be miscible alcohol and water are miscible oil and water are immiscible the maximum amount of solute that can be dissolved in a given amount of solvent is called the solubility

Tro's Introductory Chemistry, Chapter 1313 Why do we do that? we spread salt on icy roads and walkways to melt the ice we add antifreeze to car radiators to prevent the water from boiling or freezing – antifreeze is mainly ethylene glycol when we add solutes to water, it changes the freezing point and boiling point of the water

Tro's Introductory Chemistry, Chapter 1314 Colligative Properties the properties of the solution are different from the properties of the solvent any property of a solution whose value depends only on the number of dissolved solute particles is called a colligative property – it does not depend on what the solute particle is the freezing point, boiling point and osmotic pressure of a solution are colligative properties

Tro's Introductory Chemistry, Chapter 1315 Drinking Seawater Because seawater has a higher salt concentration than your cells, water flows out of your cells into the seawater to try to decrease its salt concentration. The net result is that, instead of quenching your thirst, you become dehydrated.

Tro's Introductory Chemistry, Chapter 1316 Osmotic Pressure Solvent flows through a semipermeable membrane to make the solution concentration equal on both sides of the membrane. The pressure required to stop this process is the osmotic pressure.

Tro's Introductory Chemistry, Chapter 1317 Hemolysis & Crenation normal red blood cell in an isotonic solution red blood cell in hypotonic solution – water flows into the cell – eventually causing the cell to burst red blood cell in hypertonic solution – water flows out of the cell – eventually causing the cell to distort and shrink

Chapter 618 Measurement of Solubility Molarity (M): amount of solute, in moles, per liter of solution

Chapter 619 Example 6.18 Calculate the molarity of a solution made by dissolving 3.50 mol of NaCl in enough water to produce 2.00 L of solution. Exercise 6.18A Calculate the molarity of a solution that has mol of NH 3 in 5.75 L of solution. Calculate the molarity of a solution made by dissolving mol of H 3 PO 4 in enough water to produce 775 mL of solution.

Chapter 620 Example 6.19 What is the molarity of a solution in which 333 g of potassium hydrogen carbonate is dissolved in enough water to make 10.0 L of solution? Exercise 6.19 Calculate the molarity of each of the following solutions: a mol of H 2 SO 4 in 2.00 L of solution b mol of KI in 2.39 L of solution c mol of HF in 752 mL of solution. (HF is used for etching glass.)

Chapter 621 Example 6.20 How many grams of NaCl is required to prepare L of typical over-the-counter saline solution (about 0.15 M NaCl)? Exercise 6.20 How many grams of potassium hydroxide is required to prepare each of the following solutions? a L of 6.00 M KOH b mL of 1.00 M KOH