1. Acids & Bases: The pH Scale

2. What is a solution?  A mixture containing more than 1substance Examples:

3. What’s in a solution?   Solute Substance that is dissolved in the solution   Solvent What the solute is dissolved in For example, in a salt water solution the salt is the solute and the water is the solvent Water is the UNIVERSAL SOLVENT!

4. What are some types of solutions?  Your body contains lots of solutions too! Blood Blood Saliva Saliva Stomach fluid Stomach fluid Urine Urine  Different solutions have different characteristics so they are used for different things  3 Major Types Neutral Neutral Acidic Acidic Basic/Alkaline Basic/Alkaline

5. What is the pH scale?  A scale that measures the acidy or alkalinity of a substance  The scale goes from 0 to 14 7 marks a NEUTRAL solution < 7 marks an ACIDIC solution > 7 marks a BASIC / ALKALINE solution 1414 0 7 Acid Neutral Base

6. What are the properties of a NEUTRAL solution?  pH = 7  Equal amount of hydrogen ions (H + ) and hydroxide ions (OH - )  Example: WATER! Keeps balance in your body Keeps balance in your body 2/3 of your body weight is water 2/3 of your body weight is water

7. What are the properties of an ACIDIC solution?  pH below 7 0-6.9 0-6.9  Characteristics Sour taste Sour taste Conduct electricity Conduct electricity Break down substances (corrosive) Break down substances (corrosive)  Examples: Citrus fruits Citrus fruits Battery acid Battery acid Phosphoric acid in pop Phosphoric acid in pop

8. What are the properties of a BASIC / ALKALINE solution?  pH above 7 7.1-14 7.1-14  Characteristics Bitter taste Bitter taste Slippery to touch Slippery to touch Break down substances (cleans) Break down substances (cleans)  Examples: Soaps Soaps Cleaning supplies Cleaning supplies Laxatives Laxatives

9. What are buffers?  Solutions that RESIST a change in pH  Keep adding acid or base, but the pH doesn’t change!  VERY important in the body Help keep the pH levels in your body constant Help keep the pH levels in your body constant

10. What is ?  pH is measured using ROY G BV ROY = Acid ROY = Acid G = Neutral G = Neutral BV = Base/Alkaline BV = Base/Alkaline

11. Now it’s time to write a summary! Write 3 sentences that briefly describe the topic just discussed!