The Ph of Common Substances - Lab Report Example

Most measured substances were already in the liquid state. However, lemon juice was diluted prior to the measurement while the Rolaid antacid tablet was crushed and mixed in water prior to measurement.

For the first titration run, the formed Rolaid solution was added gradually to the soda. The addition of Rolaid solution was carried out in increments of 10 mL to a maximum of 30 mL of Rolaid solution in soda. pH of the resulting solution was measured at each addition of the Rolaid solution using a pH meter.
For the second titration run, the diluted lemon juice solution was gradually added to the milk. The addition of lemon juice solution was carried out in increments of 10 mL to a maximum of 30 mL of lemon juice solution in milk. pH of the resulting solution was measured at each addition of the lemon juice solution using a pH meter.

Results
Q 1. As more and more antacid is added to the soda, the pH tends to increase. The relationship between antacids and soda shows an increasing trend. The increase in pH is greater at the beginning but tends to taper off to approach a plateau.
Q 2. As more and more lemon juice solution is added to the milk, the pH tends to decrease. The relationship between lemon juice solution and milk shows a decreasing trend. The decrease in pH is nearly constant overall leading to the conclusion that the relationship is linear.
Q 3. As more and more lemon juice solution is added to the milk, the milk tends to curdle more and more. The constant decrease in pH indicates that the lemon juice is causing curdling and a net decrease in the amount of hydrogen ions in the solution.

Q 4. The soda-antacid relationship shows an increase in pH while the lemon juice and milk relationship shows a decrease in pH.
Q 5. The Rolaid tablet tends to consume the acid in the stomach by neutralizing it. The decrease in the amount of acid in the stomach tends to aid relief.
Q 6. A buffer contains both hydrogen ions and hydroxyl ions though in weak concentrations. When an acid is added, the buffer solution consumes the hydrogen ions to keep the pH constant. When an alkali is added, the buffer solution consumes the hydroxyl ions to keep the pH constant.
Q 7. Two typical natural buffer solutions are blood and amino acids in the human body that act to keep the pH constant. Read More