CHM256 VIDEO PRESENTATION | VOLUMETRIC ANALYSIS

[00:00:03][music] >> Hi and assalamualaikum to everyone.

[00:00:07]Okay, so today I will first introduce the concept of volumetric analysis.

[00:00:11]>> [music] >> Volumetric analysis is a quantitative analytical technique that is used to determine the concentration of an unknown solution. In [music] simple words, it helps scientists find out how much of a certain substance is present in a solution. Okay, so to do this, volumetric analysis involves measuring the volume of the solution with a known solution, [music] which is called a standard solution. That is needed to react completely with the unknown solution. Okay, as shown in this diagram, >> [music] >> we start with an unknown solution, also known as the analyte.

[00:00:35]The solution contains the substance that we want to measure. Then a standard solution, also known as the titrant, is slowly added until a complete reaction occurs.

[00:00:43]>> [music] >> At the end point, where the reaction is complete, we can use the volume of the titrant added to calculate the concentration of the unknown solution.

[00:00:49]For example, if we know the concentration and volume of the standard solution, we can determine the amount of substance in the unknown solution using calculations based on the chemical equations. Okay, now let's move on to the next slide.

[00:00:58]Okay, now moving on to the principle of volumetric analysis. Volumetric analysis usually involve a reaction between two solutions, the analyte, [music] which has an unknown concentration, and the titrant, which has a known concentration.

[00:01:08]The most common technique used in volumetric analysis is titration. During titration, the titrant is placed in a burette and slowly added into the analyte in a conical flask. The purpose of adding the titrant slowly is to make sure that the reaction can be controlled accurately. An indicator [music] is usually added into the flask to help identify the end point. Okay, the end point is the point where a visible color change occurs, showing that the reaction that has been completed. For example, it will usually show as the pale pink color.

[00:01:29]>> [music] >> Okay, this diagram shows the progression of titration. Before titration begins, the solution has its original color. As the titrant is added, the color starts to change [music] when it approaches the end point. Once the end point is reached, a permanent color change can be observed. As what I told earlier, the color of pale pink will [music] always occur when the when the reaction occur.

[00:01:46]Okay, for our experiment, we apply this principle using an acid-base titration to determine the concentration of acetic acid in the vinegar. The reaction occurs between acetic acid from vinegar and sodium hydroxide solution, >> [music] >> where they react in a one-to-one ratio to produce sodium acetate and water.

[00:02:01]The volume of sodium hydroxide required to completely neutralize the acetic acid allows us to calculate the concentration of acetic acid in the vinegar sample.

[00:02:07]>> [music] >> Let's move on to the next page.

[00:02:09]Okay, so for this page, we will talk about why is volumetric analysis is very important in our daily life. Okay, so we'll talk about the applications of volumetric analysis. Okay, firstly, it [music] is involved in food industry. It determines the acidity levels in products such as vinegar, fruit juices, and dairy products.

[00:02:22]>> [music] >> It is ensures product quality and safety.

[00:02:25]From the chemical industry, it determines the amount of active ingredients in [music] medicines and also ensures correct dosage. Okay, in addition, we will talk about environmental monitoring. It measures pollutants or chemical components in water samples.

[00:02:35]So, it will be safe when we do it.

[00:02:37]>> [music] >> Okay, lastly, we will talk about the research and quality control. Used to verify quality and concentration of chemical substances.

[00:02:42]>> Okay, now, let's move on to the next slide. I will talk about vinegar, acetic acid, and the importance of determining the [music] concentration of acetic acid. First, vinegar is a sour liquid produced through the double fermentation of sugary substrates. In this process, sugar is first converted into alcohol, and then the alcohol is converted into acetic acid. This acetic acid is what gives vinegar its sour taste, strong smell, and high acidity. Vinegar [music] is commonly used as a food preservative, condiment, and also for household purposes such as cleaning and as a mild antiseptic. Next, acetic acid, also known as ethanoic acid, is the main component of vinegar. It is responsible for the sour taste and smell of vinegar.

[00:03:15]Usually, vinegar [music] contains about 4% to 6% acetic acid dissolved in water.

[00:03:19]Acetic acid is [music] also widely used in industries such as food production, plastic, dyes, pharmaceuticals, and medicines. Finally, determining the concentration of acetic acid [music] is important. It ensures the quality of vinegar by maintaining consistent acidity, flavor, and preservative properties. It is also important for quality control during production to make sure the product meets food and industry standards [music] and to detect any variation in the process. In addition, it is important for safety because different concentrations have different levels of corrosiveness. So, knowing the acid concentration helps ensure proper handling [music] and use. In conclusion, vinegar and acetic acid are important in both daily life and industrial application, and measuring its concentration is essential for quality, safety, and consistency.

[00:04:01]Okay, next I will explain the principle of acid-base titration used to determine the concentration [music] of acetic acid in vinegar. Acid-base titration is based on a neutralization reaction between an acid and a base. In this experiment, acetic acid, which is a weak acid, [music] reacts with sodium hydroxide, a strong base. A standard sodium hydroxide solution with a known concentration is gradually added to the acetic acid solution of unknown concentration [music] until the equivalence point is reached, where both substance completely react in a 1:1 stoichiometric [music] ratio. The reaction is represented by equation acetic acid reacts with sodium hydroxide to produce sodium acetate and water.

[00:04:35][music] To detect the change during titration, phenolphthalein is used as the indicator. It is colorless [music] in acidic solution and turns pale pink in slightly alkaline condition. The end point is reached when all the acetic acid has fully reacted with sodium hydroxide. This is shown by a permanent pale pink color, indicating that the neutralization [music] is complete. From this titration process, we are able to determine the concentration of acetic acid in the solution. [music] >> For methodology, to determine the concentration of acetic acid in vinegar, an acid-base titration was performed using a standard sodium hydroxide solution.

[00:05:07]>> [music] >> First, the burette was rinsed and filled with 0.100 molar sodium hydroxide [music] solution.

[00:05:12]The initial volume was then recorded.

[00:05:15]Next, 25 mL of vinegar was measured accurately using a pipette and transferred into a conical flask. Two to three [music] drops of phenolphthalein indicator were added to the vinegar sample. The solution [singing] remained colorless because it was acidic.

[00:05:26]>> [music] >> The sodium hydroxide solution was then added slowly from the burette into the conical flask while continuously swirling the flask.

[00:05:32]>> [music] >> As the titration approached the end point, the sodium hydroxide was added drop by drop. The end point was reached when a faint pink color appeared and remained visible for about 30 minutes.

[00:05:40]This color change indicated [music] that all the acetic acid had reacted with sodium hydroxide.

[00:05:44]The final burette reading was then recorded and the volume of hydroxide used was calculated.

[00:05:48]The The was repeated [music] three times to obtain more accurate and reliable results.

[00:05:52]The average titrant volume [music] was then used to calculate the concentration of acetic acid in the vinegar sample.

[00:06:02]>> [music] >> With the stoichiometric equation of HCl and NaOH sodium >> [music] >> chloride and water.

[00:06:09]From this equation we can find the mole of HCl because the information that we got from our experiment is HCl concentration is 0.1 20 20 ml and molar mass of >> [music] >> acetic acid 60 g per mole and also the result is we got an average mole of HCl is >> [music] >> uh 14.25 and average volume of NaOH is 22.45. [music] From the From the information we can have a mole of HCl.

[00:06:32]To find the mole of HCl we use the formula of mole. It is mole equal to MV over [music] 1,000.

[00:06:38]So, from the information we just fill in for uh to formula.

[00:06:41]>> [music] >> It is 0.1 uh develop with 20 uh over uh 1,000 and you will got uh 0.002 Okay.

[00:06:50]>> [music] >> Wait. We need to find uh we need to determine the MV.

[00:06:55]This is a HCl. Why we search for HCl because we only have information for HCl. So, the formula equation is we find the ratio of HCl and NaOH is the same.

[00:07:02]It is 1 over 1. So um NaOH also the same also the same mole like HCl from the answer that we got we can have a molarity of NaOH.

[00:07:10]>> [music] >> To find uh molarity of NaOH we use M over uh equal N over V. N is for mole. N is for mole. V is for volume.

[00:07:21]M is for molarity.

[00:07:22]>> [music] >> Okay.

[00:07:23]Mole We insert the answer to N. 0.002 over 0.01425 with two. And volume bracket Where can I get the volume? You can get the volume from the average volume of HCl because the ratio of um NaOH and [music] also HCl is the same.

[00:07:37]That's why we use the uh HCl um average volume.

[00:07:41]>> [music] >> You can get the is 0.1404 mol.

[00:07:44]The third step is we need to find the [music] mol of acetic acid. Acetic acid, as we know, acetic acid is H uh CH3COOH.

[00:07:51]Now, to find the mol of acetic acid, we do the equation because we are going to add NaOH. So, CH3COOH [music] + NaOH will produce CH3COONa + water.

[00:08:00]From this, you can get uh we need to find the mol like first step. So, 0.1404 over 22.45 over uh 1,000.

[00:08:10]Then, we got 0.003 mol.

[00:08:13]Like the previous [music] one, step one, the equation is this is the balanced equation. So, you need just need the the the the first one before it produce the product. Uh it shows [music] that acetic acid and NaOH they has a ratio 1/1. So, this [music] this mol of NaOH then acetic acid also have a 0.003 mol.

[00:08:30]The step four, we need to [music] search the mass of acetic acid.

[00:08:32]Formula of mass of acetic acid is a mass equal to mol and uh molar mass.

[00:08:36]The molar mass of acetic acid is a 60.

[00:08:38]>> [music] >> So, from the information, you can also get the information. Insert the information.

[00:08:41]So, the mol is 0.003 and 60, we get 0.18 >> [music] >> g.

[00:08:47]First, 10 mL of original vinegar was diluted to 100 mL of water. Next, only 20 mL of diluted solution was transferred [music] to 100 mL for titrations. Since 20 mL is 1/5 of the bottle So, if the acetic acid present in 2 mL of original vinegar for titrations, we can use it.

[00:09:05]Uh acetic acid and 100 over 2, so you will get 9.46 This is the weight of acetic acid.

[00:09:11]That's all.

[00:09:12]The percentage of weight per volume to determine The formula of uh weight of volume [music] percentage is weight over volume.

[00:09:25]So, in this [music] formula, you can search the information.

[00:09:28]9.06 g 100 mL Then, we got this. But, usually, commercial vinegar has a 4 [music] to 6% of vinegar But, from apple juice. We got 9.46%.

[00:09:41]So, >> [music] >> it's much higher than expected.

[00:09:44]Next application, the determination of acetic acid concentration in vinegar has many important applications in everyday [music] life and industry. In the food industry, manufacturers use acid with titration to ensure that vinegar products contains the correct amount of acetic acid as stated on the label.

[00:09:59][music] This helps maintain product quality and consistency.

[00:10:03]The next one is environmental analysis.

[00:10:05]It is also used in quality control laboratories to monitor [music] the production process and ensure that products meet regulatory standards.

[00:10:11]Accurate measurements [music] are essential because variations in acetic acid concentration can affect the taste, preservation properties, and overall quality [music] of vinegar.

[00:10:20]The last one is food safety authorities, meaning they check that companies that commercial vinegar products [music] comply with national food regulations.

[00:10:32]>> [music]