To find the concentration of sodium hydroxide by titrating hydrochloric acid with sodium hydroxide.
Titration is the process of determining the concentration of an unknown solution using a solution of known concentration. Titrations involve slowly adding the reagent (the titrant) to a solution containing the measured (the analyte). In addition, the titrant and analyte undergo a chemical reaction. It can also be determined by a type of indicator present in the solution or a physical change in the solution, such as pH, electrode potential, conductivity, or light absorption (color). Titration ends when this physical property abruptly changes, called an endpoint. In this case, the concentration of hydrochloric acid was given and the concentration of sodium hydroxide should be found by titrating acid and base. Firstly, the hydrochloric acid was used to a rinse burette and the burette was filled with hydrochloric acid. In addition, a pipette was used to incorporate 25 ml of sodium hydroxide into the conical flask. Phenolphthalein is used as an indicator because an acidic solution added to the indicator turns colorless, whereas in a basic solution the indicator turns pink. So, the Phenolphthalein is added to the sodium hydroxide. Hydrochloric acid is slowly released into the conical flask until a color change occurs. The endpoint is reached. This is balanced chemical reaction is
HCl+NaOH → H2O+NaCl
When this experiment is carried out the base in the conical flask should turn colorless after adding acid to the solution. The base solution should be colorless at the beginning of the experiment when the phenolphthalein indicator is added to the base solution it should turn pink and adding the acid to the solution should turn colorless.
Sodium hydroxide dependent.
so it was the independent variable
The concentration of hydrochloric acid was given as 0. dm- The concentration of Sodium hydroxide was unknown Pipette Distilled water Phenolphthalein Indicator Burette Funnel Conical flack X 4 White tile Eye protection Stand and clamp Pipette filler
Firstly, the apparatus should be rinsed with distilled water, which helps to remove the dust from the apparatuses. Consequently, it enables us to get a perfect result during titration.
Place the washed burette on the stand in the clamp. Ensures it is securely fixed and that you can clearly read the readings on the burette.
Using the funnel, hydrochloric acid was poured into the burette until 0ml was reached. The 0 ml point is the initial point of the burette. We have to fill the burette till the initial point of it to get a proper reading.
Fill the pipette with the Sodium hydroxide, and use a pipette filler. Avoid using your mouth to fill the pipette.
Ensure the level of Sodium hydroxide does not drop after removing the pipette filler from the pipette by placing the thumb on top.
By keeping the pipette in front of eye level, the lower meniscus is adjusted until the mark on the pipette is reached (25ml). Now we got exact 25ml of Sodium hydroxide.
Make sure the conical flask is under the pipette, so when you remove your thumb from the pipette. The Sodium hydroxide solution enters the conical flask without any spillage of chemicals.
When we add phenolphthalein (Phenolphthalein is often used as an indicator in acid-base titrations) to the base solution, which changes the color of the solution to pink.
Place the conical flask on the white tile, which helps the conical flask to be stable.
By opening the switch of the burette, the acid from the burette is slowly added to the conical flask. Make sure the conical flask is swirling when the acid is added to the conical flask. Swirling of the conical flask helps the base to mix well with the base solution.
Continue swirling until the solution turns pink. Then make sure the reading is noted down on paper.
Follow the same step and observed the readings three more times and record them.
As a result of this experiment conducted by me and my partner, the results were accurate. This titration was carried out to find the concentration of Hydrochloric acid by achieving the equivalent point (The point at which the titrant fully neutralizes all the titers, leaving neutral water, is called the “equivalence point.” This is when the titrant has "used up" all of the titers. The acid and base have fully canceled each other out. At equilibrium, the solution's pH is 7) (sciencing/half-equivalence-point-titration- graph-8655474) in which the color of the solution turns pink in the above titration carried out. we need to make sure that the apparatus is rinsed with the distilled water before stating the titration, if not we may end in an error reading.
The titration was conducted four times to make sure the results are accurate and the result was noted in a table. To make sure, we were able to assess the results more easily. With the exception of the first reading, all three readings should range from 0.1-0 cm3 and not exceed that.
Our tutor helped us to find PPT equipment in the laboratory and he made sure that everyone is wearing a PPT because the PPT can protect us from any kind of accident. The experiment carried out by my and partner was started with the wrong titration because there was confusion about whether the acid or base goes into the burette. Then our tutor made it clear that the hydrochloric acid goes into the burette and the 25 ml sodium hydroxide goes into a conical flask. After the clarification, we started to do the titration on the right path. In order to ensure that no mistakes were made, we followed each step with great concentration. Our experiment was error-free since we cleaned the apparatus with distilled water. Consequently, there was no change for mistakes.
During our first titration, the endpoint error occurred because we concentrated on swirling the conical flask, we forgot to keep a hand on the burette opener. This leads us to an error at the endpoint of the titration but we realize the mistake and start to be more focused on the experiment to avoid mistakes. Due to reasons like the above events, the titration is careered out more than three times to get a perfect result the titration. In addition, when the Ph indicators(phenolphthalein) were added to the sodium hydroxide, we need to make sure that only 1-2 drops of Ph indicator are added to the sodium hydroxide because when Ph indicators are added more than 1-2 drops to the sodium hydroxide leads to an error in the final reading.
In order to ensure that we do not get confused with concentration reading each time, we fill our burette until the starting point before each attempt. The challenging part of the titration is getting exactly 25 ml of sodium hydroxide using a pipette because we were using the pipette filler for the first time, approximately we took 5 mins to get the exact 25 ml of sodium hydroxide into the pipette.
The purpose of the titration is to find the concentration of the hydrochloric acid with the help of a base (sodium hydroxide) with a known concentration and a Ph indicator (phenolphthalein). In this experiment, we encountered two difficulties, but more trials helped to get more precise results. Titrations are performed by gradually adding an acidic solution to a basic solution until total neutralization is achieved. Upon neutralization, an indicator detects the end of the titration as color changes in the solution. Finally, the concentration of the given hydrochloric acid was 0 mol. dm-3.