Acid/Base Lab

Purpose: The Acid/Bases lab was designed to show and prove how acidic or basic a mixture is. The drops of .10M HCl (acid) and the .10M NaOH (base) were the two independent variables which changed the pH of the mixtures. We were trying to find out how certain materials, such as orange juice, would react to different amount of a certain base or acid.

Introduction: Different solutions have different reactions to different acids and bases. Some solutions may have a different resistance to some acids and bases than others. This allows us to see the change in pH and the total buffer range. The buffer range shows us just how resistant the solution was to the acids/bases added. This is"

Methods- during the experiment we used the "Lab Quest 2" PH sensors to test how the PH was effected when acidic and basic solutions were added to certain materials. We measured the change in PH for every five drops of an acidic or basic solution that we added to two seperate samples of our material to be tested. We then tracked the changes in PH (rise or fall) as the basic and acidic solutions were added. The data was graphed using the Lab Quest 2 devices. The graphs will be Shown below.





Data:

pH of Water

pH of Orange Juice

pH of Gelatin

Graphs and Charts: Blue = Base    Red = Acid

pH of Water

pH of Orange Juice

pH of Gelatin

Discussion: In our experiments our tested materials were water, orange juice, and gelatin. When the water was tested the solution started out roughly as a neutral solution. As the acidic and basic drops were added the PH level was drastically changed. Within ten drops there was a six PH difference between the water with the basic solution and the acid solution. And by the end of the thirty drops there was over an eight PH difference. This shows that water is highly effected by the outside additions of things of different PH. Where in the orange juice solution it started off mostly acidic and then only varied a little. The added acidic solution made the orange juice PH lower only slightly, there was only a .25 PH difference. And in the Basic solution there was a bit of an off reading. the graph dipped quite a bit, and then slowly climbed up back to normal, and then gained only .04 PH. This shows that the orange juice had very little variance in PH, there was only a variance of .26 PH. Lastly we did the experiment with a gelatin solution. This solution started off with a mostly neutral PH. Then as the different PH of solutions were added there was a variance in the PH. Unlike the orange juice the gelatin and the water were very affected by outside additions to the solution. They both ranged greatly in variance in PH but the orange juice resisted change very well.

Conclusion: The orange juice acted as the best buffer out of the 3 solutions. Its pH resisted change, even when drops of HCl and NaOH were added to it. The water was the poorest buffer because its pH changed the most when the drops of HCl and NaOH were added to it.

Refrences: We did not really use other outside references.