Acids, Bases andAcids, Bases and SolutionsSolutions

Chapter 7Chapter 7

I. Solutions, Colloids and I. Solutions, Colloids and SuspensionsSuspensions

A. WHAT IS A SOLUTION?A. WHAT IS A SOLUTION?

A solution is a uniform mixture that A solution is a uniform mixture that contains a contains a solventsolvent and a and a solute. solute.

The solvent is the part thatThe solvent is the part that is present is present in the largest amountin the largest amount. The solute is . The solute is the part present in the the part present in the smallersmaller amount amount and and is dissolved in the solvent.is dissolved in the solvent.

SolutionsSolutions

Properties of a solutionProperties of a solution The particles in a solution The particles in a solution are too are too

small to be seen.small to be seen. Light will Light will pass through a solution.pass through a solution.

SolutionsSolutions

Separating a SolutionSeparating a Solution A solution is a A solution is a mixturemixture, not a , not a

compoundcompound, so it can be separated by , so it can be separated by a a physical change.physical change.

Examples of physical changes:Examples of physical changes: *melting*melting *Boiling*Boiling *vaporization*vaporization

SolutionsSolutions

Solutions with waterSolutions with water Water is called the Water is called the “universal solvent”“universal solvent”

because so many things dissolve in it.because so many things dissolve in it. Examples:Examples: *Soda*Soda *Tea*Tea *Blood, sweat and tears*Blood, sweat and tears

SolutionsSolutions

Solutions without water-Solutions without water- not all solutions use water as the not all solutions use water as the

solvent;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 * Dental fillings- solid in liquid (mercury)(mercury)

II. ConcentrationII. Concentration

Concentration: Concentration: a measure of the a measure of the amount of solute (grams) dissolved amount of solute (grams) dissolved into an amount of solvent (milliliters)into an amount of solvent (milliliters) Dilute solution – Dilute solution – a small amount of a small amount of

solute in a given amount of solventsolute in a given amount of solvent

Concentrated solution – Concentrated solution – a large amount a large amount of solute in a given amount of solventof solute in a given amount of solvent

III. SolubilityIII. Solubility Solubility is a measure of Solubility is a measure of how much how much

solute can dissolve into a solvent at a solute can dissolve into a solvent at a given temperature.given temperature.

Saturated solution: Saturated solution: you have added you have added all the solute that a solvent can hold.all the solute that a solvent can hold.

No more solute will dissolve into the No more solute will dissolve into the solventsolvent

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

for acids?for acids?

What are properties of bases?What are properties of bases? What are some common uses What are some common uses

for bases?for bases?

IV. Acids, Bases, and SaltsIV. Acids, Bases, and Salts

A. Acids – A. Acids – Any compound that Any compound that increases the number of increases the number of hydrogen ions (Hhydrogen ions (H+1+1) when ) when dissolved in Hdissolved in H22OO

AcidsAcids Properties of acids:Properties of acids:

1. sour taste, corrosive1. sour taste, corrosive2. react with metals2. react with metals3. reacts with carbonates3. reacts with carbonates4. changes color of an indicator:4. changes color of an indicator:

Blue litmus Blue litmus turns red in the turns red in the presence of an acidpresence of an acid

Red litmus Red litmus stays redstays red5. pH number less than 75. pH number less than 7

Uses of acids: Uses of acids: many vitamins are acidsmany vitamins are acidsAcidic cleanersAcidic cleanersFolic acid is an important vitamin for Folic acid is an important vitamin for cell growthcell growth

Nitric acid and phosphoric acid are Nitric acid and phosphoric acid are used in fertilizersused in fertilizers

Sulfuric acid can be found in Sulfuric acid can be found in batteriesbatteries

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

Properties of bases:Properties of bases:1. bitter taste 1. bitter taste 2. slippery to touch2. slippery to touch3. changes color of an 3. changes color of an indicator:indicator:

Red litmus Red litmus turns blue in the turns blue in the presence of a basepresence of a base

Blue litmus Blue litmus stays bluestays blue4. pH number greater than 74. pH number greater than 7

Uses of bases:Uses of bases:1. Ammonia solutions are 1. Ammonia solutions are good household cleanersgood household cleaners

2. Baking soda in cooking 2. Baking soda in cooking reacts with acids to form COreacts with acids to form CO22 bubbles that add texture to bubbles that add texture to foodfood

3. Mortar and cement are 3. Mortar and cement are made from basesmade from bases

Section 4 essential Section 4 essential questionsquestions

How do you measure the How do you measure the strength of acids and strength of acids and bases?bases?

How do acids and bases How do acids and bases react with one another?react with one another?

Strong versus weak Strong versus weak acids:acids:Strong: Strong: when most when most molecules of an acid break molecules of an acid break apart in water to produce apart in water to produce hydrogen ionshydrogen ions

Weak: Weak: when only a few when only a few molecules break apartmolecules break apart

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

Weak: Weak: when only a few when only a few molecules break apartmolecules break apart

pH ScalepH Scale pH scale: pH scale: pH is the measure of the concentration of pH is the measure of the concentration of

Hydrogen ionsHydrogen ions pH scale measures pH scale measures how strong or weak acids and bases arehow strong or weak acids and bases are

Goes from 0 to 14Goes from 0 to 14

00 1 2 3 4 5 1 2 3 4 5 66 7 7 8 9 10 11 12 138 9 10 11 12 13 1414StrongStrong weak weak N N weakweak strongstrongAcidAcid acid acid basebase basebase

N = Neutral, not an acid or a base (ex. water)N = Neutral, not an acid or a base (ex. water)

II. Acids, Bases, and SaltsII. Acids, Bases, and SaltsD: acids and bases neutralize each D: acids and bases neutralize each

other –other – The The HH++ of the acids and the of the acids and the OHOH-- of of

the base react to make the base react to make HH22OO Metal (positive ion) from base & Metal (positive ion) from base &

nonmetal (negative ion) from acid nonmetal (negative ion) from acid make a make a saltsalt

Add these items to your pH Add these items to your pH scalescale

Stomach acid Stomach acid 11 Lemon juiceLemon juice 22 GrapesGrapes 33 TomatoTomato 44 BananasBananas 55 MilkMilk 66 WaterWater 77 EggsEggs 88 Baking sodaBaking soda 99 SoapSoap 1010 AmmoniaAmmonia 1212 LyeLye 1414

E. SaltsE. Salts

Ionic compound formed Ionic compound formed from the positive ion of from the positive ion of the base (a metal) and the the base (a metal) and the negative ion of the acid (a negative ion of the acid (a nonmetal)nonmetal)

NaOH + HCl NaCl + HNaOH + HCl NaCl + H22OO

Base + acidBase + acid salt + watersalt + water

Uses of Salts:Uses of Salts:

1. Not just for french fries1. Not just for french fries

2. make lye, plasterboard, de-ice 2. make lye, plasterboard, de-ice roads.roads.