Title:
To what extent does strong and weak acids differ in affecting the course of titrations.
Introduction:
The real life application that comes from this experiment links to agriculture. In the past decade, industrial dumping has become a controversial topic. Dumping hazardous wastes into river, ocean, and soil has resulted in a dramatic change in pH of the non-renewable resources and leads to a destruction in the ecosystem. Specially in agriculture, crops cannot grow in acidic soil, so it is crucial to maintain the acidity of the soil at a neutral state. Consequently, farmers use lime fertilizers such as powdered limestone, CaO, or the ashes of burnt wood to neutralize the acid in the soil. However, considering that the change in acids …show more content…
This is because simply by taking the medium value of the pH indicator to obtain the pH level at the equivalence point does not mean NaOH is completely dissociated at that point. In fact, we need to graph two straight line for the data before and after the equivalence point, with addition a vertical line in order to graph a line of best fit for the data to estimate the equivalence point. By using the titration curve method, the result obtained would have greater precision and accuracy. Furthermore, the two titration curves have the same shape with an gradual increase in pH before the equivalence point, a dramatic jump at the equivalence point, with an addition of continuous increase in pH after the equivalence point. However, the only difference between the two titration curves is the equivalence point is at different pH level. HCl has an equivalence point at pH 7.5 while HCOOH is at pH 8.7. This is because the product salt formed from the two reaction has different pH level, which results in different equivalence point. According to the table in Part 4 of the report sheet, when the salt NH4Cl is dissociated into water, it forms ammonium ion and hydronium ion. As hydronium ion increases in the reaction, the pH of the solution is more acidic, which is why the …show more content…
Even though the experimental result has a large error comparing to the literature value, yet, the result shows that the strong acid HCl formed the salt, NaCl, when reacting with NaOH has resulted in a natural pH level of 7.5 for its equivalence point as the strong base and strong acid are both completely dissociated so the salt does not form any hydronium or hydroxide ion in water. Yet, the weak acid HCCOH formed the salt, HCOONa, when reacting with NaOH results in a basic pH level at 8.7 for its equivalence point. This is because when HCOONa reacts with water, it forms formic acid and the hydroxide ion. Hence, the solution would be more basic than HCl, which is why by having the same shape for the titration curve, the HCOOH titration curve shifts to the right compared to the HCl titration curve. Hence, linking back to our real life application, if we are using strong base like NaOH to neutralize the acidic soil, the volume of NaOH used in a weak acid soil is less than the volume used in a strong acid soil because the strong acid completely dissociates with the strong base, while weak acid is
To what extent does strong and weak acids differ in affecting the course of titrations.
Introduction:
The real life application that comes from this experiment links to agriculture. In the past decade, industrial dumping has become a controversial topic. Dumping hazardous wastes into river, ocean, and soil has resulted in a dramatic change in pH of the non-renewable resources and leads to a destruction in the ecosystem. Specially in agriculture, crops cannot grow in acidic soil, so it is crucial to maintain the acidity of the soil at a neutral state. Consequently, farmers use lime fertilizers such as powdered limestone, CaO, or the ashes of burnt wood to neutralize the acid in the soil. However, considering that the change in acids …show more content…
This is because simply by taking the medium value of the pH indicator to obtain the pH level at the equivalence point does not mean NaOH is completely dissociated at that point. In fact, we need to graph two straight line for the data before and after the equivalence point, with addition a vertical line in order to graph a line of best fit for the data to estimate the equivalence point. By using the titration curve method, the result obtained would have greater precision and accuracy. Furthermore, the two titration curves have the same shape with an gradual increase in pH before the equivalence point, a dramatic jump at the equivalence point, with an addition of continuous increase in pH after the equivalence point. However, the only difference between the two titration curves is the equivalence point is at different pH level. HCl has an equivalence point at pH 7.5 while HCOOH is at pH 8.7. This is because the product salt formed from the two reaction has different pH level, which results in different equivalence point. According to the table in Part 4 of the report sheet, when the salt NH4Cl is dissociated into water, it forms ammonium ion and hydronium ion. As hydronium ion increases in the reaction, the pH of the solution is more acidic, which is why the …show more content…
Even though the experimental result has a large error comparing to the literature value, yet, the result shows that the strong acid HCl formed the salt, NaCl, when reacting with NaOH has resulted in a natural pH level of 7.5 for its equivalence point as the strong base and strong acid are both completely dissociated so the salt does not form any hydronium or hydroxide ion in water. Yet, the weak acid HCCOH formed the salt, HCOONa, when reacting with NaOH results in a basic pH level at 8.7 for its equivalence point. This is because when HCOONa reacts with water, it forms formic acid and the hydroxide ion. Hence, the solution would be more basic than HCl, which is why by having the same shape for the titration curve, the HCOOH titration curve shifts to the right compared to the HCl titration curve. Hence, linking back to our real life application, if we are using strong base like NaOH to neutralize the acidic soil, the volume of NaOH used in a weak acid soil is less than the volume used in a strong acid soil because the strong acid completely dissociates with the strong base, while weak acid is