S-142 What is a 1. A solution 2. An acid 3. A base

SPS6 Students will investigate the properties of solutions a.Describe solutions in terms of -solute/solvent -Conductivity -Concentration b.Observe factors affecting the rate a solute dissolves in a specific solvent c.Demonstrate that solubility is related to temperature by constructing a solubility curve d.Compare and contrast the components and properties of acids and bases e.Determine whether common household substances are acidic, basic, or neutral Unit 8 Solutions, Acids, & Bases

What are two processes that can occur when substances dissolve? What are some properties of solutions that differ from those of its solvent and solutes? What factors affect the rate of dissolving? 8.1 Formation of Solutions

Dissolving –Solution – homogeneous mixture of two or more substances –Two components Solute – substances whose particles are dissolving Solvent – substance in which the solute dissolves –Can be solids, liquids, or gases –Most common solutions are dissolved in water 8.1 Formation of Solutions What are three processes that can occur when substances dissolve?

Two ways substances dissolve –Dissociation of Ionic Compounds First an ionic compound separates into ions Called dissociation Positive and negative ions are now attracted to the polar ends of a water molecules 8.1 Formation of Solutions What are two processes that can occur when substances dissolve? Salt Dissolving

Two ways substances dissolve –Dispersion of Molecular Compounds Dispersion – spreading Particles break into small pieces and spread throughout the solvent Small pieces = molecules 8.1 Formation of Solutions What are two processes that can occur when substances dissolve?

Solutions Properties –Conductivity Solutions formed by dissociation have lots of ion Ions allow the flow of electricity –Freezing Point Solutions have lower freezing points than either the solvent or the solute –Salt and ice –Boiling Point Solutions have higher boiling points than either the solvent or the solute –antifreeze 8.1 Formation of Solutions What are some properties of a solution that differ from those of its parts

Factors Affecting Rates of Dissolving –Surface area Greater are – faster Crushed particles have a larger surface area –Temperature Higher temperatures cause more frequent collisions –Stirring Increases the collisions with the surface 8.1 Formation of Solutions What factors affect the rate of dissolving?

S-143 What are the three ways to increase the rate at which a solute dissolves? What is the difference between dissociation and dispersion?

How are solutions with different amounts of solute described? What factors determine the solubility of a solute? What are three ways to measure the concentration of a solution? 8.2 Solubility & Concentration

Solubility –The maximum amount of solute that can dissolve in a solute –At a specific temperature –For example: 36.0 g of salt will dissolve in 100g of water at 20 o C 8.2 Solubility & Concentration How are solutions with different amounts of solute described?

Solubility –Saturated – as much solute as the solvent can hold at a given temperature –Unsaturated – less than the maximum amount of solute –Supersaturated – more than the maximum Solutions are heated, solute dissolved, then they are cooled off 8.2 Solubility & Concentration How are solutions with different amounts of solute described?

Factors Affecting Solubility –Polarity – like dissolves like Polar molecules will dissolve polar Nonpolar will dissolve nonpolar –Temperature Most solids become more soluble with an increase in temperature Most gases become less soluble –Pressure – increases solubility of gases 8.2 Solubility & Concentration What factors determine the solubility of a solute?

Concentration –The amount of solute dissolved in a solvent –Percent by volume –Might have to calculate volume of solution (solute + solvent) 8.2 Solubility & Concentration What are three ways to measure the concentration of a solution?

Concentration –Percent by Mass 8.2 Solubility & Concentration What are three ways to measure the concentration of a solution?

Concentration –Molarity –Need to calculate the number of moles first –Then plug into equation for molarity 8.2 Solubility & Concentration What are three ways to measure the concentration of a solution?

S g of Iron (III) Acetate, Fe(C 2 H 3 O 2 ) 3, is dissolved in L of water. What is the A. Molar mass of the substance? B. Number of moles of the solute? C. Molarity of the solution?

S mL of methanol is dissolved in water to make 92 mL of solution. What is the A. Total volume of the solution? B. The percent by mass of the solution?

S g of copper (I) oxide is dissolved in 415 g (0.415 L) of water. A. What is the total mass of the solution? B. What is the percent by mass of the solution? C. What is the molar mass of copper (I) oxide? D. What is the molarity of the solution?

What are some general properties of acids and bases? What are the products of neutralization? 8.3 Properties of Acids & Bases

Acids –Produces H+ ions when dissolved Sometimes written as hydronium (H 3 O + ) –Sour Citrus fruits – citric acid (lemons, limes, oranges) Vinegar –Reacts with Metals Dissolves metals Single replacement reaction where metal replaces hydrogen and hydrogen gas is formed 8.3 Properties of Acids & Bases What are some general properties of acids and bases?

Acids –Indicator changes Substances that change color in the presence of an acid or base Turns blue litmus paper pink 8.3 Properties of Acids & Bases What are some general properties of acids and bases?

Bases –Produce OH- ions in solution –Bitter Unsweet chocolate Cough syrup –Dissolves organic substances You – feel slippery –Skin is dissolving 8.3 Properties of Acids & Bases What are some general properties of acids and bases?

Bases –Indicators Changes pink litmus paper blue 8.3 Properties of Acids & Bases What are some general properties of acids and bases?

Neutralization –The reaction between an acid and a base Produces water and a salt Salt – negative ion from acid combines with the positive ion from the base For example 8.3 Properties of Acids & Bases What are the products of neutralization?

S-147 What are four properties of A. Acids B. Bases

S-148 Complete the following acid base neutralization reations H 2 S + KOH  Mg(OH) 2 + HF 

How is pH used to describe the concentration of acids and bases? How do strong acids and bases differ from weak acids and bases? 8.4 Strength of Acids & Bases

The pH scale –Measures the H+ ion concentration in a solution –7 is neutral (water) –Acids from less than 7 to 0 –Bases from greater than 7 to 14 –General pH values 8.4 Strength of Acids & Bases How is pH used to describe the concentration of acids and bases?

Strong Acids and Bases –Acids – completely ionize Completely fall apart into H+ and A- Sulfuric Acid, Nitric Acid, Hydrochloric Acid –Bases – completely dissociate Completely fall apart into B+ and OH- Calcium Hydroxide, Potassium Hydroxide, Sodium Hydroxide 8.4 Strength of Acids & Bases How do strong acids and bases differ from weak acids and bases?

Weak Acids and Bases –Acids – slightly ionize Only a part of the acid fall apart into H+ and A- Acetic Acid (vinegar) –Bases – slightly dissociate Only partially fall apart into B+ and OH- Ammonia 8.4 Strength of Acids & Bases How do strong acids and bases differ from weak acids and bases?

Important –Concentration and Strength are different –Concentration – how much is dissolved –Strength – how much of the dissolved acid/base will fall apart 8.4 Strength of Acids & Bases How do strong acids and bases differ from weak acids and bases?