I am doing a home lab experiment about acid-base neutralization. I just need a little help to see if I am doing it correctly.
I completed the experiment and recorded the data.
We were to add 25 ml of vinegar and the 1 ml of cabbage indicator, the add i ml of ammonia at a time to reach a total of 35 ml of ammonia solution.
I observed when approx when 1-2 ml of ammonia was added the solution was neutralized.
Here are the problems I am having:
1. If we were to assume that the vinegar and ammonia reacted in a 1:1 ratio how do the relative concentrations compare?
2. In order to calculate the actual concentration of ammonia what would we require from the neutralized reation?
I think we would need to know the amount of vinegar in mL, and concentration in mols/L as well as pH
3. Could we observe a neutralization by adding vinegar to an ammonia solution?
I think yes because if we add vinegar to the solution it reverses back to pink/red.
A. The data and experimental details are too scant/vague to make sense of the questions.
Your #1. The relative concns can be estimated by the ratio of the volumes used.
Your #2. You would need mL and M of vinegar and mL of ammonia. I don't think the pH of either is needed.
Your #3. No, you can not observe a neutralization between ammonia and acetic acid BECAUSE:
a. ammonia is a weak base.
b. vingar is a weak acid.
c. weak acids titrated against weak bases (or the other way around, too) do NOT have a sharp change in pH at the equivalence point; therefore, the indicator does not have sharp color change. In these titrations, the true equivalence point is never determined.
Here are the answers to your questions step-by-step:
1. If we assume that the vinegar and ammonia reacted in a 1:1 ratio, the relative concentrations can be compared by looking at the volume of vinegar and ammonia added. In this experiment, you added 25 ml of vinegar and gradually added 10 ml of ammonia solution. Therefore, the concentration of vinegar is higher than the concentration of ammonia in this reaction.
2. To calculate the actual concentration of ammonia, you would need information from the neutralized reaction. Specifically, you would need to know the volume of vinegar used (25 ml) and its concentration in moles per liter (mol/L). With this information, you can use stoichiometry to determine the number of moles of vinegar reacted, which is equal to the number of moles of ammonia. Then, by dividing the moles of ammonia by the volume of ammonia solution added (35 ml), you can calculate the concentration of ammonia.
3. Yes, you can observe a neutralization by adding vinegar to an ammonia solution. When vinegar (an acid) is added to an ammonia solution (a base), a neutralization reaction occurs. This reaction forms water and a salt. The cabbage indicator used in your experiment changes color to indicate acidity or alkalinity. So when you add vinegar to the ammonia solution, the indicator may change color indicating the formation of a salt and water as a result of the neutralization reaction.
1. To compare the relative concentrations of vinegar and ammonia in the neutralization reaction, you would need to know the amount of vinegar and ammonia added to the solution.
Since you added 25 mL of vinegar and gradually added 1 mL increments of ammonia until a total of 35 mL of ammonia solution was reached, you can assume that you added somewhere between 10-11 mL of ammonia to reach neutralization. Based on this, you can conclude that the amount of vinegar used is approximately 25 mL, and the amount of ammonia used is approximately 10-11 mL.
2. To calculate the actual concentration of ammonia in the neutralized reaction, you would need the volume and molarity of the vinegar, as well as the volume and molarity of the ammonia solution.
Concentration is defined as the amount of solute (in this case, ammonia) dissolved in a given volume of solution. In order to calculate concentration, you need to know the number of moles of ammonia present in the solution.
To find the number of moles of ammonia, you would first determine the number of moles of vinegar present. This can be calculated by using the volume and molarity of the vinegar solution. Then, since the reaction is assumed to be in a 1:1 ratio, the number of moles of ammonia would be equal to the number of moles of vinegar.
Once you have the number of moles of ammonia, you can calculate the concentration by dividing the number of moles by the volume of the ammonia solution.
3. Yes, you can observe a neutralization by adding vinegar to an ammonia solution. In the neutralization reaction between an acid (vinegar) and a base (ammonia), the acid donates a proton (H+) to the base, resulting in the formation of water and a salt.
When vinegar is added to an ammonia solution, the reaction occurs in the reverse direction. The basic nature of ammonia reacts with the acidic nature of vinegar, resulting in the formation of ammonium ions and an acetate ion. This reaction brings the pH closer to neutral, causing the solution to change back to its original color.
The color change in your experiment from pink/red back to its original color confirms that the neutralization reaction occurred.