In this lab, the pH of flat sprite and a fresh sprite are compared two ways: one way was to record the pH directly with a digital pH probe and the other was to calculate the concentration through titration. Because the reaction is a neutralization reaction, the concentration of can be calculated if the concentration of is known. At the end of the titration, the moles of will equal the moles of and the pH is expected to be greater than 7 because the found in sprite is weak and is a strong base. The pH of both the fresh sprite as well as the flat sprite were measured with a pH probe before any titration for comparison.
The initial pH of the flat sprite was higher because had bubbled out and when dissolves in the sprite, it makes . Therefore, controls the pH by introducing extra into the solution. However, this is not the primary acid in sprite. The primary acid is . , which is found in sprite, buffers the solution. Therefore, Sprite is a buffer. The titration removes all including those produced by and . Therefore, at the neutralization point, there are no remaining. We would expect the calculated pH of the titrated sprit to be higher because there are no more remaining ions. The difference between flat and fresh sprite is that the fresh sprite has more in it. This is because ionizes to a small percentage, producing ions. This lowers the pH as well as . The pH of the flat and fresh sprite were not exactly the same but very close to each other. The reason is because the solution is buffered. Any ions produced by the bubbles in sprite are consumed by as shown in the equation . Overall, Sprite along with probably majority of soft drinks, are buffered because they are being ingested and the body is sensitive to changes in pH. The pH of Sprite is between 3 and 4 while the pH of water is 7. A pH of 3 is 10,000 times more acidic than a pH of 7. While the weak acids found in sprite produce small amounts of , the titration...
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