Report and Data Sheet.
Report & Data Sheet
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| Name | Started: 01/28/22 Finished: 01/ |
Exercise 1. Measuring pH Using Red Cabbage Indicator
Table 1. pH indicator color data
| Household Substance | Color Observed | pH | H3O+ Conc. (H+) Decimal equivalent |
| Baking powder | Greenish color | 10 Base | H_30^+ 10^-10 |
| Water | Dark/bluish color | 7 Neutral | H_30^+ 10^-7 |
| Lemon juice | Red/orangish color | 2 Acidic | H_30^+ 10^-2 |
| Sugar solution | Turquoise/bluish color | 9 Neutral | H_30^+ 10^-9 |
| Vinigar | Dark/reddish color | 3 Acidic | H_30^+ 10^-3 |
Instructions: The questions are in the first row of each table. You will write your answers in the second row. The cell will expand as you type.
| From your results, which items were acidic and which were basic? Did you expect these results? |
| Maalox and Alka Seltzer are items that relieve acid indigestion. From what you learned in this lab, how do you think that this medicine works to relieve acid indigestion? |
| When carbon dioxide combines with water, it forms carbonic acid. The bubbles in soda are just carbon dioxide gas and this is what makes soda acidic. Excess carbon dioxide in our atmosphere is causing a lot of problems. One of those is Global Warming but what other issues can it cause? Think about how this can impact the pH of rain and the oceans. |
Exercise 2. Virtually Measuring pH of Common Household Substances
Table 2. pH of Common Household Items
| Common Household Substance | pH value | Acid/Base | H3O+ Conc. (H+) Decimal equivalent | OH- Conc. Decimal equivalent |
| Water | 7.00 | Neutral | H_3O^+ 10^-7 | 1*10^- 7 |
| Coffee | 5.00 | Acidic | H_3O^+ 10^-5 | 1*10^-9 |
| Hand soap | 10.00 | Basic | H_3O^+ 10^-10 | 1*10^-4 |
| Soda pop | 2.50 | Acidic | H_3O^+ 10^-2 | 1*10^-12 |
| Orange juice | 3.50 | Acidic | H_3O^+ 10^-3 | 1*10^-11 |
| Battery acid | 1.00 | Acidic | H_3O^+ 10^-1 | 1*10^-13 |
| Blood | 7.40 | Basic | H_3O^+ 10^-7 | 1*10^-7 |
| Drain cleaner | 13.00 | Basic | H_3O^+ 10^-13 | 1*10^-1 |
| Black coffee has a pH around 5; hand soap has a pH of 10. How many times more acidic is coffee relative to hand soap? |
| Drain cleaner has a pH of 13; hand soap has a pH of 10. How many times more basic is drain cleaner relative to hand soap? |
| Black coffee has a pH around 5; battery acid has a pH of 1. How many times more acidic is battery acid relative to black coffee? |
Exercise 3. Determining the Buffering Capacity of an Unknown Buffer
| Briefly explain the function of a buffer. |
| A common student misconception about buffers is that buffers neutralize solutions. Explain why this is incorrect. |
| Is water a good buffer? |
| Why did we use a LabQuest and pH probe to gather pH data for the Unknown Buffers rather than a pH indicator? |
| Briefly explain the difference between pH range and buffering capacity. You may need to refer back to the introduction section of this lab. |
| List the Unknown Buffer Assigned to you in the space below. |
Exercise 4. Graphing Your Unknown Buffer
| Paste your scientific figure, showing the titration graph of your assigned unknown buffer in the space below. Review all of the components of a scientific figure and ensure you have incorporated all of the necessary elements. (Hint: a good figure includes a descriptive figure caption.) |
| The titration curve to my unknown buffer is
|
| What is the buffering capacity for your buffer? |
| What is the pH range for your buffer? |
