Acids, Bases, & pH Section 2.6.

Slides:



Advertisements
Similar presentations
Water Chapter 3. Water Life began in water 2/3s of an organisms body Organisms grow or reproduce in a water-rich environment.
Advertisements

PH.
Acids and Bases. How acidic a substance is, or how basic a substance is, is measured on a scale known as the pH scale. This is a logarithmic scale that.
Acids and Bases. Think back to a time when you have eaten something very sour… Think back to a time when you have eaten something very bitter… What were.
Strength of Acids and Bases. What makes a strong acid or base?  The strength of an acid or base is based on how many acid or base particles break down.
Indicators and Hydrogen Ions and Acidity
Bellringer What is an acid? What is a base?
Basic Chemistry for Biology Water and Solutions. Water’s Life Supporting Properties Important to all living things 1.Moderation of temperature 2.Lower.
Chapter 3: Water & Life. 1.I can explain the significance of polar covalent and hydrogen bonds within and between water molecules. a.I can determine how.
Water essential for life (as we know it!) any other chemical with this low of a molecular weight = GAS (but it’s a liquid at room temp!) b/c of it’s polarity,
CHAPTER 2 The Chemical Basis of Life
Chapter 3: Water & Life. 1.I can explain the significance of polar covalent and hydrogen bonds within and between water molecules. a.I can determine how.
 Bonds of Water- strong › Can break into hydrogen ion (H + ) and hydroxide ion (OH - ) H 2 O  H + + OH -
Chemistry of Life. Atoms Greek for “indivisible” Smallest possible particle of an element element Made up of Proton (+) Neutron(=)Electron(-) Nucleus=
Unit 4 Acids, Bases and pH. Water molecules dissociate and ionize to form H 2 0  H + + OH - Water  hydrogen ion + hydroxide ion In pure water, there.
Acids and Bases Ch. 2 Pre-AP Biology Ms. Haut. Despite strong bonds in water molecules, a portion of bonds break, forming a H + and OH - Despite strong.
Chapter 3 Water and the Fitness of the Environment.
Chemistry Basics -Part Two. Covalent Bonds Can Be Nonpolar Or Polar… Remember that covalent bonds occur between atoms that share electrons. There are.
BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Neil A. Campbell Jane B. Reece Lawrence.
Acids & Bases. pH scale Ranges from 0-14 Ranges from – 6 = Acid 0 – 6 = Acid 0 is most acidic 0 is most acidic Concentration of H + (hydrogen or.
Figure Water is Central to Life Water has several properties that life is dependent upon including: Cohesion High heat of vaporization High specific.
Acids & Bases. pH scale Ranges from 1-14 Ranges from – 6 = Acid 1 – 6 = Acid 1 is most acidic 1 is most acidic Concentration of H + (hydrogen)
Acids and Bases.
Learning Check pH2 The [OH-] of a solution is 5 x M. What is the [H 3 O + ] of the solution? 1) 2 x M 2) 1 x M 3) 2 x M.
Fig Fig. 3-2 Hydrogen bond  – – H  + + H O — —  + +  + +  + +  – –  – –  – –
Acids & Bases.
Acids and Bases Notes and Questions Ms. Haapala. Acids and Bases Standard 5 Acids, bases, and salts are three classes of compounds that form ions in water.
Acids, Bases, and pH A water molecule can react to form ions. Water   Hydrogen ion + Hydroxide ion.
Acids & Bases. Indicators Indicators contain certain dyes which change color at various pH values. Indicators contain certain dyes which change color.
Acids, Bases & pH. Acids Has positive hydrogen ions (H+) Has positive hydrogen ions (H+) Sour Taste Sour Taste Reacts with Metals and Carbonates Reacts.
PROPERTIES OF WATER.
PH and Titration Notes Honors Chemistry.
They are everywhere.. In your food In your house EVEN IN YOU!!!!!
PH.
Concept 3.3: Acidic and basic conditions affect living organisms
 – Hydrogen bond  + H —— O  –  + —— H  –  +  –  +
Ready Acids and Bases.
Acids and Bases--pH.
Chapter 3 (p.46-56) Water & Life.
Chemistry of Life.
Water Chemistry and Acid/Base Review
Concept 3.3: Acidic and basic conditions affect living organisms
Water Chemistry and Acid/Base Review
Goals to Accomplish Today
Unit One Water and Life.
Acids, Bases and Salts In this section we look at the properties of acids and bases, find out what salts are, and how to prepare them.
Acid / Base Worksheet Answer the questions to the Acid/Base worksheet by clicking through the following slides that were made by you and your classmates.
2.9 Water is a polar molecule
Acids and Bases SPS6. Students will investigate the properties of solutions. d. Compare and contrast the components and properties of acids and bases.
Acids and Bases Chapter 23
Acids, Bases, and pH A water molecule can react to form ions.
Do now Pollutants have the ability to cause the pH of a substance to change especially in aqueous solutions. Why do you think pH is related to water.
Acids and Bases.
Concept 3.3: Acidic and basic conditions affect living organisms
Fig. 3-1 Figure 3.1 Why does the abundance of water allow life to exist on the planet Earth?
Chapter 7 – Acids, Bases and Solutions
Acids and Bases By Danya Ardis.
Properties of Water! Why Water is Special.
Essential Question: What makes water unique compared to other substances? Do Now: Explain why do you think water is important for life? HW: Water properties.
PH.
Acids, Bases, & pH TSW differentiate between acids and bases, and explain the importance of pH to organisms.
CHAPTER 2 The Chemical Basis of Life
Aim: How can we describe the various properties of water
Matter, Chemical Bonds, Chemical Reactions
Definitions Indicators and Measurements
Acids & Bases.
Acids and Bases.
pH Scale Strengths of Acids and Bases
Physical Science Chapter 23
Water is the biological medium on Earth
Presentation transcript:

Acids, Bases, & pH Section 2.6

Learning Objectives Contrast acids and bases & discuss their properties. Convert the hydrogen ion concentration of a solution to a pH value. Describe how buffers help minimize changes in pH.

Pure Water is Neutral Water dissociates into hydrogen ions (H+) and hydroxide ions (OH-) One water molecule breaks down into one of each ion H+ and OH- are equal in concentration Since H+ and OH- are equal in concentration pure water is neutral pH = 7

Acids & Bases Acid = a solution that has more hydrogen ions (H+) than hydroxide ions (OH-) pH < 7 Donates H+ ions Base = a solution that has more hydroxide ions (OH-) than hydrogen ions (H+) pH > 7 Accepts H+ ions

(Higher concentration of H+) (Lower concentration of H+) pH scale The pH Scale Each pH unit represents a tenfold change in concentration of H+ Logarithmic scale H+ OH– Lemon juice; gastric juice (Higher concentration of H+) Increasingly ACIDIC Grapefruit juice Acidic solution Tomato juice Urine NEUTRAL [H+] = [OH–] PURE WATER Human blood Seawater Neutral solution (Lower concentration of H+) Increasingly BASIC Milk of magnesia Household ammonia Household bleach Oven cleaner Basic solution Figure 2.15

pH Indicators http://pbskids.org/zoom/activities/sci/cabbagejuiceindicato.html Boiled cabbage creates a bluish juice that can be used to test pH of substances Turns blue in bases Turns red in acids http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/Grafik/cabbage.gif

pH Indicators Other indicators: pH paper Blue litmus paper Turns red in acids Red litmus paper Turns blue in bases phenolphthalein turns pink in presence of bases http://www.bio-world.com/images/061036.jpg http://www.howe.k12.ok.us/~jimaskew/litmus.jpg http://ull.chemistry.uakron.edu/organic_lab/distribution/dist13.gif

Calculating Ion Concentrations [H+] [OH-] = 1 x 10-14 Ex. If [H+] = 0.001, then what is the [OH-]? Answer: [OH-] = 1 x 10-11 pH 7 is 1 x 10-7 Practice Problem: What pH is a solution that has a [H+] of 1 x 10-10 ? Answer: pH 10

Buffers Buffer = substance that resists pH change Accepts H+ ions when they are in excess and donates H+ ions when they are depleted Cells need a stable pH in order to function properly Most cells have a pH close to 7