Chapter Menu Lesson 1: Solutions Lesson 2: Acidic, Basic, and Neutral Solutions Click on a hyperlink to view the corresponding lesson.

9.1 Solutions substance mixture homogeneous mixture heterogeneous mixture solution solute solvent

9.1 Solutions Types of Matter A substance is matter that has the same composition and properties throughout. Most of the substances you encounter daily are solutions. Elements and compounds are substances.

9.1 Solutions Types of Matter (cont.) A mixture is a combination of two or more substances that can be separated by physical means. Heterogeneous mixtures are mixtures in which the substances are not evenly mixed, such as granite or mixed nuts.

9.1 Solutions Types of Matter (cont.) Homogenous mixtures are two or more substances that are evenly mixed on the atomic level.

Types of Matter (cont.) A solution is a homogeneous mixture. 9.1 Solutions Types of Matter (cont.) A solution is a homogeneous mixture. Two or more substances are evenly mixed, but they each retain their identities. Before the drink mix dissolves, the mixture is heterogeneous. When the drink mix has dissolved, it is a homogeneous mixture.

Components of Solutions The solute in any solution is the dissolved substance. The solvent is the substance used to dissolve the solute.

9.1 Solutions Types of Solutions Substances in each of the three states of matter—solid, liquid, gas—may act as solute or solvent.

Types of Solutions (cont.)

Alloys—Solid Solutions An alloy is the mixture of a metal and one or more additional elements. Alloys have metallic properties. Alloys are used in jewelry, statues, and automobiles.

Separating Mixtures by Physical Means 9.1 Solutions Separating Mixtures by Physical Means Components of a mixture can be separated by taking advantage of the differences in their physical properties. Dissolving, evaporating, melting, and freezing are some physical changes that can also be used to separate mixtures.

Solubility—How much can dissolve? 9.1 Solutions Solubility—How much can dissolve? Solubility is the measure of how much solute can be dissolved in an amount of solvent. Increasing temperature increases the ability of a solvent to dissolve a solute.

Saturated and Unsaturated Solutions A saturated solution has dissolved the maximum amount of solute at a given temperature—more solute will not dissolve in the solution. Unsaturated solutions are any solutions that are able to dissolve more solute at a given temperature—more solute can be added and it will dissolve.

Concentration—How much is dissolved? 9.1 Solutions Concentration—How much is dissolved? The concentration of a solution is the amount of solute present in a solution compared to the amount of solvent. Concentrated solutions contain a lot of solute. Diluted solutions contain little solute.

Concentration in Grams Per Liter (g/L) 9.1 Solutions Concentration in Grams Per Liter (g/L) To be precise, describe concentration as grams of solute per liter of solvent. 10 grams of sodium chloride in 1 liter of water is a concentration of 10 g/L.

9.1 Solutions Percent By Volume Percent by volume is the volume of solute in a given volume of solvent. Hydrogen peroxide is 3 percent by volume, so 3 mL of hydrogen peroxide are in every 100 mL of solution.

9.1 Solutions Water as a Solvent Most of the water on Earth is present in the form of a solution. Water is often called the universal solvent since many substances are soluble in it.

Water as a Solvent (cont.) 9.1 Solutions Water as a Solvent (cont.) Water is a polar molecule—it has a positive end and a negative end.

Polar Solvents and Polar Molecules 9.1 Solutions Polar Solvents and Polar Molecules Polar solvent molecules are likely to dissolve other polar molecules. The negative and positive ends of polar solutes are pulled into solution by the attraction to the negative and positive ends of the solvent molecules.

Polar Solvents and Polar Molecules (cont.) 9.1 Solutions Polar Solvents and Polar Molecules (cont.)

Polar Solvents and Ionic Compounds 9.1 Solutions Polar Solvents and Ionic Compounds Many ionic compounds are soluble in water. Water molecules attach themselves to the ions and pull them apart.

Conductivity of Aqueous Solutions Ions in solution allow the solution to carry an electric current. Any compound that produces ions in water is called an electrolyte.

Conductivity of Aqueous Solutions (cont.) Electricity flows through a sodium chloride solution but not a sugar solution.

NaCl is a ____ solution. A heterogeneous B homogeneous C saturated 9.1 Solutions A B C D NaCl is a ____ solution. A heterogeneous B homogeneous C saturated D none of the above Lesson 1 Review

A polar solvent contains molecules that ____. 9.1 Solutions A B C D A polar solvent contains molecules that ____. A have positive and negative ends B have magnetic ends C are saturated D have ionic bonds Lesson 1 Review

Which contains the largest amount of solute in 100 mL? A 10 g/L 9.1 Solutions A B C D Which contains the largest amount of solute in 100 mL? A 10 g/L B 20 g/L C 15 g/L D 18 g/L Lesson 1 Review

End of Lesson 1

9.2 Acidic, Basic, and Neutral Solutions hydronium ion base pH indicator pH meter

9.2 Acidic, Basic, and Neutral Solutions Acids Acids are substances that release a positively charged hydrogen ion, H+, in water. The pH scale measures the acidity of a solution. How is the acidic concentration of a solution determined?

9.2 Acidic, Basic, and Neutral Solutions What is a hydronium ion? When an acid dissolves, it releases a hydrogen ion. The H+ ion combines with water to form H3O+, the positively charged hydronium ion. Hydrogen ion Water molecule Hydronium ion

What is a hydronium ion? (cont.) 9.2 Acidic, Basic, and Neutral Solutions What is a hydronium ion? (cont.)

9.2 Acidic, Basic, and Neutral Solutions Uses of Acids Acids are important in several body processes, including breaking down food in the stomach. Acids are also used in making many products, such as fertilizers, detergent, and cleaners.

9.2 Acidic, Basic, and Neutral Solutions Bases Bases are substances that produce negatively charged hydroxide ions when dissolved in water. Most bases are ionic compounds

9.2 Acidic, Basic, and Neutral Solutions What is a hydroxide ion? In water, bases separate into a positive ion and the hydroxide ion (OH–). All the properties of bases are a result of the presence of hydroxide ions that form when the base is dissolved in water.

Uses of Bases Common bases include baking soda and cleaning agents. 9.2 Acidic, Basic, and Neutral Solutions Uses of Bases Common bases include baking soda and cleaning agents. Bases are also used to produce new products, such as soap, paper, and plaster. Acids and Bases

9.2 Acidic, Basic, and Neutral Solutions What is pH? pH is a numerical scale used to indicate how acidic or basic a solution is. The pH scale runs from 0 to 14. Acids are below 7; strong acids are near 0. Bases are above 7; strong bases near 14. Neutral solutions have a pH of 7.

pH and Hydronium Ion Concentration 9.2 Acidic, Basic, and Neutral Solutions pH and Hydronium Ion Concentration pH is the measure of the concentration of hydronium ions, H3O+, in solution. When the H3O+ concentration increases, pH decreases.

Hydronium Ions, Hydroxide Ions, and pH 9.2 Acidic, Basic, and Neutral Solutions Hydronium Ions, Hydroxide Ions, and pH All acid and base solutions contain both hydronium and hydroxide ions.

Hydronium Ions, Hydroxide Ions, and pH (cont.) 9.2 Acidic, Basic, and Neutral Solutions Hydronium Ions, Hydroxide Ions, and pH (cont.) Acids have a greater hydronium ion concentration. Bases have a greater hydroxide ion concentration.

9.2 Acidic, Basic, and Neutral Solutions Comparing pH Values Each unit on the pH scale represents a 10-fold increase. An acid with a pH of 1 contains 10 times as many H3O+ ions as an acid with a pH of 2.

Neutralization pH Values 9.2 Acidic, Basic, and Neutral Solutions Neutralization pH Values Acids and bases react together to neutralize each other. Stomach acid reacts with magnesium hydroxide in the following equation: 2HCl + Mg(OH)2 → MgCl2 + 2H2O Neither the products is acidic or basic.

9.2 Acidic, Basic, and Neutral Solutions How is pH measured? Indicators are compounds that change color within a particular pH range. Indicators can be used to determine approximate pH.

How is pH measured? (cont.) 9.2 Acidic, Basic, and Neutral Solutions How is pH measured? (cont.)

9.2 Acidic, Basic, and Neutral Solutions pH Strips Litmus is one of the simplest indicator test papers but also the least accurate. pH testing strips are a quick way of determining the approximate pH of a solution.

9.2 Acidic, Basic, and Neutral Solutions pH Meters pH meters are electronic instruments with an electrode that is sensitive to hydronium ions present in a solution. Accurately measures pH Requires an electric source to operate

9.2 Acidic, Basic, and Neutral Solutions pH Meters (cont.)

9.2 Acidic, Basic, and Neutral Solutions An acid with a pH of 3 is contains how many times as many hydronium ions as an acid with a pH of 6? A 1000 B 3 C 30 D 100 Lesson 2 Review

When an acid and base are mixed, the products are ____ and ____. 9.2 Acidic, Basic, and Neutral Solutions A B C D When an acid and base are mixed, the products are ____ and ____. A water; a base B water; ammonia C water; salt D ammonia; salt Lesson 2 Review

9.2 Acidic, Basic, and Neutral Solutions Red litmus paper is dipped in a solution. The paper turns blue. The solution must have been ____. A acidic B homogeneous C basic D polar Lesson 2 Review

End of Lesson 2

Chapter Resources Menu Chapter Assessment California Standards Practice Concepts in Motion Image Bank Science Online Interactive Table Virtual Lab BrainPOP Click on a hyperlink to view the corresponding feature.

Blue litmus paper turns ____ in acid solutions. A red B orange C green D blue Chapter Assessment 1

Which of the following is a hydroxide ion? A H3O+ B H+ C OH– D NH4+ Chapter Assessment 2

Which is a property of a base? A sour taste B produces OH– in water C produces H+ in water D reacts with metal to produce hydrogen gas Chapter Assessment 3

Which of the following is NOT a homogeneous mixture? A vinegar B brass D Which of the following is NOT a homogeneous mixture? A vinegar B brass C salt water D none of the above Chapter Assessment 4

A B C D What ions are present in the greatest amount in a solution with a pH of 2.5? A hydroxide B hydrogen C hydronium D oxygen Chapter Assessment 5

SCI 7.c A B C D When MgCl2 is dissolved in water, what term is used to describe the MgCl2? A solution B solute C solvent D alloy CA Standards Practice 1

SCI 7.c A B C D As the temperature of water decreases, its ability to dissolve NaCl ____. A increases B decreases C stays the same D cannot be predicted CA Standards Practice 2

Water is polar and easily dissolves ____ molecules. A polar B nonpolar SCI 7.c A B C D Water is polar and easily dissolves ____ molecules. A polar B nonpolar C positively charged D negatively charged CA Standards Practice 3

SCI 5.e A B C D Acids and bases are both ____ because they allow water to conduct electricity. A malleable B diluted C polar D electrolytes CA Standards Practice 4

What is the symbol for the hydrogen ion? A H3O+ B H2O C H+ D OH– SCI 5.e A B C D What is the symbol for the hydrogen ion? A H3O+ B H2O C H+ D OH– CA Standards Practice 5

Concepts in Motion 1

Concepts in Motion 2

Concepts in Motion 3

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