Probe Into The Beaker Of Tap Water example essay topic

TJ Gentile Bio lab 11/18/2003 Mrs. Trunfio Experiment 3: Acids and Bases Hypothesis: My Hypothesis is that Aspirin would be the Best buffer because it has a strong acid content and it May be able to withstand changes better. Materials Needed: -CBL System -TI Graphing Calculator -Venire pH System -Venire DIN adapter Cable -250- mL beaker -Various Biological Organisms -Various Non Biological Organisms -Graphical Analysis or graph paper -. 10 M HCI (ACID) with Dropper -. 10 M NaOH (Base) with Dropper -50 mL graduated cylinder -One rinse bottle with distilled water -Goggles -Lab Apron -50- mL beaker -Various simple biologic al Materials Procedure: 1. Obtain and Wear goggles 2.

Before each use of the pH probe you need to rinse the tip of the electrode thoroughly with distilled water. 3. Prepare the pH system for data collection -plug in pH amp -connect the CBL system and TI Graphing Calc. 4.

Turn in CBL unit and Calc. and start the CHEM BIO Program and proceed to the MAIN MENU 5. Set up calculator and CBL for the pH probe -Select SET UP PROBES -Enter 1 as the number of probes -Select PH from the SELECT PROBE menu -Enter 1 as the channel number -Select USE STORED from the CALIBRATION menu 6. Set up the Calc. and CBL for data collection -Select collect data from main menu -Select trigger prompt from the Data Collection menu -Allow 30 seconds for the pH probe to warm up and then press [Enter} -- TESTING THE EFFECT ON ACID WATER! a 7. Label a 50- mL beaker acidic and put 20 mL of water in it 8. Rinse the pH probe and place into beaker to be tested 9.

You are ready to begin making pH measurements. Monitor the pH readings displayed on the CBL screen when you get stable rating press [Trigger] on the CBL 10. The calculator will prompt you for the number of drops of acid you added to the beaker. Type 0 and press [enter] 11.

Add 5 drops of acid to the beaker. Stir thoroughly after addition. CAUTION: Handle with care 12. When reading the stable press the [Trigger] button on the CBL and enter the total number of drops of acid added to the water in the beaker and press enter 13. REPEATE ST PES 11-12 adding 5 drops each time until a total of 30 drops are added 14. On the Calc. select the option STOP AND GRAPH from the DATA COLLECTION menu.

A graph will be displayed with pH along the y- axis and the number of drops added along the x axis 15. Rinse the pH probe thoroughly and place the probe into the beaker of Tap Water. Clean the beaker. 16. On the Calc. press [enter] and select YES from the REPEATE menu REPEATE STEPS 8-16 substituting Base for acid and Then continue the Steps for each of the Other materials Table 1 MATERIAL TESTED ACID pH after adding this many drops 0 5 10 15 20 25 30 Delta PH Buffer TAP ACID 7.38 3.47 2.88 2.54 2.37 2.25?

15.61 BASE 2.91 3.13 3.09 3.33 2.49 2.62 2.67! yen. ORGANISMS BIO. CHEM NON BIO. CHEM. Orange Juice Aspirin Salt Water Egg Whites Ant-Acid Soda TABLE 3 Material Buffer Rank Tap 9.29 Worst Salt Water 9.39 2 Soda 7.35 3 Egg White 6.73 4 Orange Juice 2.52 5 Ant- Acid 2.61 6 Aspirin.

61 Best QUESTIONS: 1. How should the pH of a material in the Acidic beaker compare to that in the Basic beaker? The results should be near opposites, the Base is almost always higher in pH then the Acid beaker material 2. Referring to Questions 1, do you support your hypothesis? If not, What might be the cause of the differences? The Data of my experiment does support the hypothesis.

3. Generally, what was the effect of adding HCI to each solution? Was it true for every solution? Why do you think this happened the way it did? What happened most times you added the acid would be that the pH would get lower and lower with the more drops you added. This happened to almost every solution quite in the same way (with varying results of course) but when something did not follow the pattern it meant that the product was able to withstand the HCI better then other ones.

4. Generally what was the effect of adding NaOH to each solution? Was this true for every solution? Why do you think that this happened the way it did? When NaOH was added to the solutions they got higher and higher as the amount of drops increased. This happened along the same sort of pattern the whole time.

The reason I think it followed the same sort of pattern is because water is a pure substance and it didn! t add anything special to the solution. 5. Compare the various graphs of each substance. Why was it beneficial to include the plot of water in acid and water in base with every experiment. This was helpful because sometimes by adding products the start of each product is a little off and it ensures better more efficient notes. 6.

Which class of materials reacted most dramatically to the addition of acid or base? How does this relate to their complexity? The Group that reacted most dramatically had to be the Non- Biological Chemicals. 7. Which of the materials in Table 3 is the best buffer? The Poorest?

The best buffer is Aspirin and the worst is of course Tap Water.