Solutions, Acids, and Bases Chapter 8 Solutions, Acids, and Bases

8.1 Formation of Solutions DISSOLVING Recall that a solution is a _____________ ________of two or more substances. ______- substance whose particles are dissolved in a substance. ______-The substance in which the solute dissolves. These can be _____, ______, or _____. Most familiar is liquids.

3 WAYS TO FORM SOLUTIONS Substances can dissolve in liquids in three ways: __________, __________, and ___________ DISSOCIATION OF ______ COMPOUNDS The particles that hold solutes to each other and solvents to each other must be overcome. Ex: NaCl is an ionic compound. Water is a polar molecule, and is attracted to the salt. The sodium and chlorine ions are pulled into solution one by one. Dissociation-The process in which an ionic compound separates into ____ as it ______________. When an ionic compound dissolves in water, the charged ends of water molecules surround the oppositely charged ions.

3 WAYS TO FORM SOLUTIONS DISPERSION OF ___________ COMPOUNDS Ex: Sugar and water are both polar molecules, so they attract one another. When the attractions between them are great enough to overcome the __________ holding the sugar molecule to the surface of the crystal, The sugar molecule breaks free, and is pulled into solution by the water molecules. Dispersion-Breaking into small ________ that spread throughout the water. Saliva dissolves the sugar in hard candy by dispersion. As water molecules collide with sugar crystals, attractions develop between the water molecules and sugar molecules at the ________ of the solid.

3 WAYS TO FORM SOLUTIONS IONIZATION OF MOLECULAR COMPOUNDS When HCl dissolves in water the hydrogen atom gets pulled away from chlorine and forms a hydronium ion.  Ionization-_________molecules gain or lose electrons. This is different from the previous two because it is a _________ change. The solution that results contains ____substances.

Properties of Liquid Solutions Only ______ physical properties of a solution will differ from those of its solute and solvent. They are ___________, ____________, and ________________. CONDUCTIVITY When NaCl is dissolved in water, the ion are free to ______. This will conduct an electric __________. NaCl ____ dissolved will not conduct a current.

Properties of Liquid Solutions FREEZING POINT AND MELTING POINT MgCl2 is used in winter to melt ice and snow. It ____________ into its ions. The structure of ice is __________ by the ions and cannot freeze. Coolant is added to cars to _____ the boiling point and prevent the car from overheating. The presence of solute particles affects how a solvent freezes. A Pure water freezes in a hexagonal pattern. B In water “salted” with MgCl2, the dissociated Mg2+ and Cl− ions ______ the formation of ice crystals.

HEAT OF SOLUTION During the formation of a solution, energy is either _________ or _________. Like chemical reactions, this is described as endothermic or exothermic. In order for a solution to form, bonds must be ________, and new attractions _______. Breaking attractions ________ energy The formation of attractions ________ energy The difference in these energies is known as the ______________.

FACTORS AFFECTING RATES OF DISSOLVING Like rates of chemical reactions, rates of dissolving depend on the __________and ________ of collisions that occur between very small particles. Factors that affect the rate of dissolving include ___________, _________, and _________________.

Surface Area When a sugar cube dissolves in water, the dissolving takes place at the _______ of the cube. The _______ the surface area of a solid solute, the more _________ the collisions are between solute and solvent particles. More collisions result in a_________rate of dissolving

Stirring Stirring moves dissolved particles away from the _____ of the solid, and allows for ____ collisions between solute and solvent particles. Stirring will make it dissolve _______. The rate of dissolving can be increased by reducing the particle size of the solute, by stirring, and by heating the solvent.

Temperature Increasing the temperature of a solvent causes its particles to move _______, on average. As a result, both the number of _________ and the ________ of these collisions with solute particles increase. The solute goes into solution more quickly. Increase in temp. will _______________the rate of dissolving.

8.2 Solubility & Concentration Solubility- The __________ amount of a solute that dissolves in a given amount of solvent at a constant ______________ Solubilities are usually expressed in grams of ______ per 100 grams of ________ at a specified temperature At a given temperature, different solutes have different solubilities in water.

3 Ways Solutions are Classified Solutions are described as __________, ____________, or _____________, depending on the amount of solute in solution. Saturated Solutions - contains as much solute as the solvent can _____ at a given temperature The solvent is “_______” with solute. If you add more solute, it will ____ dissolve.

3 Ways Solutions are Classified Unsaturated Solution - A solution that has ____ than the maximum amount of solute that can be dissolved Supersaturated Solution is one that contains _____ solute than it can normally hold at a given temperature. Supersaturated solutions are very ______. If even a tiny crystal of the solute falls into a supersaturated solution, the extra solute can rapidly ____________of solution If you heat a solvent up, more solute may dissolve. Then you then ______ cool the solvent back without jarring it, you may be able to keep the _________________in solution. In the photo sequence, a single crystal of sodium acetate, NaC2H3O2, is added to a supersaturated solution of sodium acetate in water. The excess solute rapidly crystallizes out of the solution.

Factors Affecting Solubility Three factors that affect the solubility of a solute are the _________ of the solvent, ______________, and ____________ Generally, a solute is more likely to dissolve in a “like” solvent than an “unlike” solvent.

Polar and Nonpolar Solvents Oil does not dissolve in water because oil molecules are __________ and water molecules are _______. guideline for predicting solubility is “____ dissolves _____.” Soaps and detergents are used to remove grease and oil stains. Soap molecules form attractions to both polar water molecules and nonpolar oil molecules. As the water flows away, it carries the oil with it.

Temperature In general, the solubility of solids increases as the solvent temperature ___________ When a glass of cold water warms up to room temperature, bubbles form on the inside of the glass. These bubbles are _______ that were dissolved in the water. They come out of the solution as the water temperature________. Unlike most solids, gases usually become _____soluble as the temperature of the solvent ____________.

Pressure Increasing the pressure on a gas ____________ its solubility in a liquid. The pressure of CO2 in a sealed 12-ounce can of soda at room temperature can be two to three times ________________ pressure

Concentration of Solutions Concentration of a solution-the amount of solute dissolved in a ___________ amount of solution Concentration of solution is usually expressed as % by _______ or % by _______. Percent by volume = Useful when dealing with liquids Percent by mass = Useful when solute is a solid

8.3 Properties of Acids and Bases Identifying Acids Acid- a compound that produces __________ ions (H3O+) when dissolved in water.

Properties of Acids Sour Taste Lemons, grapefruits, limes, and oranges have ____ acid Vinegar has _________ acid Spoiled dairy products have _________ acid NEVER TEST AN ACID BY TASTING IT

Properties of Acids Reactivity with Metals Color Changes in indicators Acids and metals undergo a __________________ reaction Color Changes in indicators _________ – any substance that changes color in the presence of an acid or base. Ex: Blue Litmus paper turns____

Identifying Bases Base- a compound that produces __________ ions (OH-) when dissolved in water.

Properties of Bases Bitter Taste Slippery Feel Unsweetened (baking) chocolate Slippery Feel Wet__________ Wet_________ Color Changes in Indicators Red Litmus paper turns ____ in a base Phenolphthalein turns red Hydrangeas turn blue in acid soil, pink in basic soil

Neutralization and Salts The reaction between an acid and a base is called ________________ Negative ions in an acid combine with the positive ions in a base to produce an ionic compound called a ______________

The pH Scale pH scale – a number scale from __________used to describe the concentration of hydronium ions in a solution. A ________tells you that the concentration of H+ ions is _____. (acid) A _______tells you that the concentration of H+ ions is ____. (base) pH lower than 7 = ________ (0-6) pH higher than 7 = __________ (8-14) pH of 7 = _______