1. Do Now Please write HW in your agenda. Please update your table of contents and take sheets from the front cart. You haven’t learned this yet, but try to figure out what makes a strong acid strong and a weak acid weak. Discuss your thoughts with your tablemates. Page #TitleDate 1 - 1The pH Scale2/23

2. Acids and Bases in Solution What type of ion is formed when an acid is put into water? What type of ion is formed when a base is put into water?

3. Strength of Acids and Bases Even if an acid or a base is dilute, it can still be strong! ▫ Concentrated: not much water ▫ Dilute: a lot of water compared to acid/base The strength of an acid or base depends on how likely it is to form hydronium or hydroxide ions. Strength of an acid or a base is measured on the pH scale.

4. Weak acid vs. strong acid Weak acid Strong acid

5. Weak base vs. strong base

6. pH Scale The pH of a substance is an inverse measure of the concentration of H 3 O + ions in a solution. As H 3 O + …pH…

7. pH Scale The pH scale is logarithmic. -For acids this means that moving down a number below 7 increases the number of H 3 O + by a multiple of 10. -For bases this means that moving up a number above 7 increases the number of HO - by a multiple of 10.

8. pH Foldable Color in the pH scale according to the universal indicator colors: Leave the spaces on the side open for tomorrow’s lab! pH RangeDescriptionColor 0-3Strong acidRed 3-6AcidOrange/Yellow 7NeutralGreen 8-11BaseBlue 11-14Strong baseViolet

9. Indicator

10. Answer on an index card… 1. What kinds of ions do acids and bases form in water? 2. What does a substance’s pH tell you? 3. If a solution has a pH of 6, would it contain more or fewer H 3 O + ions than an equal volume of a solution with a pH of 3?