Acids, Bases and Solutions Chapter 7

I. Solutions, Colloids and Suspensions A. WHAT IS A SOLUTION? A. WHAT IS A SOLUTION? A solution is a uniform mixture that contains a solvent and a solute. A solution is a uniform mixture that contains a solvent and a solute. The solvent is the part that is present in the largest amount. The solute is the part present in the smaller amount and is dissolved in the solvent. The solvent is the part that is present in the largest amount. The solute is the part present in the smaller amount and is dissolved in the solvent.

Solutions Properties of a solution The particles in a solution are too small to be seen. The particles in a solution are too small to be seen. Light will pass through a solution. Light will pass through a solution.

Solutions Separating a Solution A solution is a mixture, not a compound, so it can be separated by a physical change. A solution is a mixture, not a compound, so it can be separated by a physical change. Examples of physical changes: Examples of physical changes: *melting *melting *Boiling *Boiling *vaporization *vaporization

Solutions Solutions with water Water is called the “universal solvent” because so many things dissolve in it. Water is called the “universal solvent” because so many things dissolve in it. Examples: Examples: *Soda *Soda *Tea *Tea *Blood, sweat and tears *Blood, sweat and tears

Solutions Solutions without water- not all solutions use water as the solvent; not all solutions use water as the solvent; Examples: Examples: * Air- gases in gases * Air- gases in gases * Stainless steel-solids in solids * Stainless steel-solids in solids * Dental fillings- solid in liquid (mercury) * Dental fillings- solid in liquid (mercury)

II. Concentration Concentration: a measure of the amount of solute (grams) dissolved into an amount of solvent (milliliters) Concentration: a measure of the amount of solute (grams) dissolved into an amount of solvent (milliliters) Dilute solution – a small amount of solute in a given amount of solvent Dilute solution – a small amount of solute in a given amount of solvent Concentrated solution – a large amount of solute in a given amount of solvent Concentrated solution – a large amount of solute in a given amount of solvent

III. Solubility Solubility is a measure of how much solute can dissolve into a solvent at a given temperature. Solubility is a measure of how much solute can dissolve into a solvent at a given temperature. Saturated solution: you have added all the solute that a solvent can hold. Saturated solution: you have added all the solute that a solvent can hold. No more solute will dissolve into the solvent No more solute will dissolve into the solvent

Essential questions sect 3 What are properties of acids? What are properties of acids? What are some common uses for acids? What are some common uses for acids? What are properties of bases? What are properties of bases? What are some common uses for bases? What are some common uses for bases?

IV. Acids, Bases, and Salts A. Acids – A. Acids – Any compound that increases the number of hydrogen ions (H +1 ) when dissolved in H 2 O Any compound that increases the number of hydrogen ions (H +1 ) when dissolved in H 2 O

Acids Properties of acids: Properties of acids: 1. sour taste, corrosive 1. sour taste, corrosive 2. react with metals 2. react with metals 3. reacts with carbonates 3. reacts with carbonates 4. changes color of an indicator: 4. changes color of an indicator: Blue litmus turns red in the presence of an acid Blue litmus turns red in the presence of an acid Red litmus stays red Red litmus stays red 5. pH number less than 7 5. pH number less than 7

Uses of acids: Uses of acids: many vitamins are acids many vitamins are acids Acidic cleaners Acidic cleaners Folic acid is an important vitamin for cell growth Folic acid is an important vitamin for cell growth Nitric acid and phosphoric acid are used in fertilizers Nitric acid and phosphoric acid are used in fertilizers Sulfuric acid can be found in batteries Sulfuric acid can be found in batteries

B. Bases B. Bases Any compound that increases the number of hydroxide ions (OH -1 ) when it dissolves in water Any compound that increases the number of hydroxide ions (OH -1 ) when it dissolves in water

Properties of bases: Properties of bases: 1. bitter taste 1. bitter taste 2. slippery to touch 2. slippery to touch 3. changes color of an indicator: 3. changes color of an indicator: Red litmus turns blue in the presence of a base Red litmus turns blue in the presence of a base Blue litmus stays blue Blue litmus stays blue 4. pH number greater than 7 4. pH number greater than 7

Uses of bases: Uses of bases: 1. Ammonia solutions are good household cleaners 1. Ammonia solutions are good household cleaners 2. Baking soda in cooking reacts with acids to form CO 2 bubbles that add texture to food 2. Baking soda in cooking reacts with acids to form CO 2 bubbles that add texture to food 3. Mortar and cement are made from bases 3. Mortar and cement are made from bases

Section 4 essential questions How do you measure the strength of acids and bases? How do you measure the strength of acids and bases? How do acids and bases react with one another? How do acids and bases react with one another?

Strong versus weak acids: Strong versus weak acids: Strong: when most molecules of an acid break apart in water to produce hydrogen ions Strong: when most molecules of an acid break apart in water to produce hydrogen ions Weak: when only a few molecules break apart Weak: when only a few molecules break apart

Strong versus weak bases: Strong versus weak bases: Strong: when all molecules of a base break apart in water to produce hydroxide ions Strong: when all molecules of a base break apart in water to produce hydroxide ions Weak: when only a few molecules break apart Weak: when only a few molecules break apart

pH Scale pH scale: pH is the measure of the concentration of Hydrogen ions pH scale: pH is the measure of the concentration of Hydrogen ions pH scale measures how strong or weak acids and bases are pH scale measures how strong or weak acids and bases are Goes from 0 to Strong weak Nweakstrong Acid acidbasebase N = Neutral, not an acid or a base (ex. water)

II. Acids, Bases, and Salts D: acids and bases neutralize each other – The H + of the acids and the OH - of the base react to make H 2 O The H + of the acids and the OH - of the base react to make H 2 O Metal (positive ion) from base & nonmetal (negative ion) from acid make a salt Metal (positive ion) from base & nonmetal (negative ion) from acid make a salt

Add these items to your pH scale Stomach acid 1 Stomach acid 1 Lemon juice2 Lemon juice2 Grapes3 Grapes3 Tomato4 Tomato4 Bananas5 Bananas5 Milk6 Milk6 Water7 Water7 Eggs8 Eggs8 Baking soda9 Baking soda9 Soap10 Soap10 Ammonia12 Ammonia12 Lye14 Lye14

E. Salts E. Salts Ionic compound formed from the positive ion of the base (a metal) and the negative ion of the acid (a nonmetal) Ionic compound formed from the positive ion of the base (a metal) and the negative ion of the acid (a nonmetal) NaOH + HCl NaCl + H 2 O NaOH + HCl NaCl + H 2 O Base + acidsalt + water Base + acidsalt + water

Uses of Salts: 1. Not just for french fries 2. make lye, plasterboard, de-ice roads.