1. 4.1 – Describe how acids and bases in solution affect certain indicators 4.2 Determine the pH of a solution using a universal indicator PH SCALE

2. A scale of values that show how basic or acidic a substance is based on an assigned number http://www.downsizingamerica.com/images/ph_scale.gif Strongest

4. You have a glass of orange juice that has a pH of 3. What can you conclude about the orange juice? It is an ACID You have some drain cleaner that has a pH of 13.5. What can you conclude? It is a BASE You have some distilled water. What can you conclude about the pH? It is NEUTRAL, so pH = 7

5. Which of the following substances would definitely have a pH under 7? H 2 SO 4 HClH2OH2O CaCl 2 CH 4 KOHMg(OH) 2 pH under 7 = ACIDS

6. http://www.fishdoc.co.uk/images/pH_scale.gif 5 X 10 x 10 x 10 x 10….and so on If substance A has a pH of 1 & substance B has a pH of 3, which is MORE ACIDIC? Substance A – it is actually 100 times more acidic!!!

7. Rank from most acidic to least acidic:  Vinegar pH 2  Bleach pH 13  Milk pH 6.5  Coffee pH 5 VinegarMilkBleachCoffee Least acidic Most acidic

8. Rank from least basic to most basic:  Blood pH 7.4  Sea Water pH 8  Bananas pH 5  Drain Cleaner pH 13.5 BananasSea WaterDrain CleanerBlood Most Basic Least Basic

9. http://www.miamisci.org/ph/ Great internet site to explore….. Try the following three links on this site (EXCITE, EXPLORE and EXTEND) and play the interactive activities which will help you better understand pH!!

10. Indicators are chemical dyes that turn different colours when they are placed in acidic and alkaline (basic) solutions

11. Methyl Red is an indicator & its colour change is shown below. pH Scale Indicator 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Methyl Red REDOrangeYellow If this indicator where placed in a solution with a pH of 6, what colour would it turn? Orange If this indicator where placed in a solution with a pH of 11.5, what colour would it turn? Yellow

12. The table below shows various indicators If you have a solution of pH 5, what colour will it turn in each indicator? Yellow Red Yellow/Orange Colorless Yellow

13. Universal Indicator (pH paper) is a special indicator. Like Litmus Paper, it uses color, but a much larger range of colors, closely identifying the pH of a solution relatively accurately. Notice the color range… red shows very strong acid orange/yellow is a weaker acid green is neutral blue/indigo shows weak base purple/violet shows strong base

14.  Worksheet #7  Study guide, Module 3, page 22, 23, 24, 25 and 26

15. References:  Google Images  Microsoft Clip Art