how to prepared 100ml 0.1m standard oxalic acid solution #11thchemistry #11thpractical #practical

Hello everyone and welcome to my channel. My name is Sachin Supla and you are watching A to Z Practicals. In A to Z Practicals, I will cover all the practicals of 9th, 10th, 11th, and 12th grades. Today, I'm starting the first activity of the 11th. Its aim is to prepare 100 ml of 0.1 normal oxalic acid solution. How can we prepare a 0.1 molar oxalic acid solution? I'm going to tell you today. Let's begin the experiment. First of all, we need to know the formula for normality. Then only can we calculate it. I am going to tell you the formula for normality. Now, we are going to determine the number of grams of oxalic acid. For that, we are going to use the formula for molarity. So, molarity is equal to weight divided by molecular weight, multiplied by 1 divided by volume in dm³. Clear? 1 per cubic decimeter. Now, you know that the molecular weight of oxalic acid is 126 grams. How much is it? 126. And how many moles do we need to produce? As shown in 1, we need to prepare 0.1 moles. So, the formula for molarity is 0.1. We have to determine the weight. The molecular weight of oxalic acid is 126 g per liter in dm³. Volume in cubic decimeters is equal to 100 milliliters. So, 100 ml will be divided by 1000. Thus, you will obtain volume in cubic decimeters. What will you get? 0.1 Now, you will put 0.1 here. If you have to make 200 ml, you will divide 200 by 1000. If you have to make 300, you will divide 300 by 1000. So, whatever you get here, you will put it here. Now, I will calculate all of this. 0.1 into 1.26 into 0.1. So, this will be your W. Multiply all of this, and you will get 1.26. So, this will be your W. That means you have to weigh 1.26 grams of oxalic acid. And you have to make 100 ml of it. If you need to make 200 or 300 ml, Then you will put 300 here. If you have to change the molarity, if you have to make 0.2 Then you will put 0.2 here. If you have to make 0.3, Then you will put 0.3 here. If you need to adjust the volume, Then you will change 100 here. And according to that, you will obtain the weight. Now, we are going to use this weight. to make the next solution. Clear? Friends, this is our weighing machine. where we weigh the material. This is called a watch glass. What is this watch glass? In this, we measure all the material. What do we do through this? We put it in here and measure. If you place the watch glass here, Then it will display its weight. We need to weigh 1.26 grams of oxalic acid. But it's already showing 17 grams here. So, what do we need to do to weigh oxalic acid? This weight has to be negligible. Otherwise, if you put anything in it, It will show greater weight. As soon as you put it here, Tear it first. Tear means we will make it zero. Now, if we put anything in it, It will display its weight. As we learned from the calculation that we have to weigh 1.26 grams of oxalic acid. I'm putting it in now. How much is this? It is 1.24 grams. This is the tear weight. And I have weighed 1.26 grams here. Now, what do we have to do with this? We will dissolve it in 100 ml. For that, we are going to use a volumetric flask. And in the volumetric flask, We are going to dissolve it in 100 ml. Guys, you can also do it in Beaker. But we don't use it in the beaker. because our beaker is not exactly 100 ml. To prepare the stock solution, We must use a standard measuring flask. It gives us pure 100 ml. Guys, we've now weighed it 1.26 grams of oxalic acid. Now, what should I do with this oxalic acid? I will transfer it. in this small beaker of 50–60 ml. Now, guys, if we transfer it here, then some particles Get stuck in it. So, we have to remove these particles We have to remove them. in a pure way Now, I will take a measuring cylinder and pour some water into it. Or you can directly pour some water into it. You can pour some water into it. Now, pour some water into it. Again, guys, We have to wash it over and over again. We have to wash it over and over again. We have to wash it so thoroughly that it contains some particles of oxalic acid. It will reduce our concentration. For this, we have to wash it. 2 to 3 times. Now, guys, You can take 50 ml of water. How much water will you take? You will add 50 ml of water in it Now, guys, We will dissolve it thoroughly. You will check it. It will be dissolved. While dissolving it, Remember one thing. All the particles should be thoroughly dissolved. You have to check it again and again. whether it is dissolved or not. Now, guys, it's dissolved. Now, what I will do is This is called a standard measuring flask. You must have read that. You must create a standard solution. What I said at the beginning that you have to create a standard solution. The standard measuring flask that you are seeing, volumetric flask It is also called a volumetric flask and a standard measuring flask. It is 100 ml. How do you know it's 100 ml? There is a lining here. You can see this lining. Basically, this lining is here. When you see it, you will know. You can see this lining. If you feel the liquid then you will know that this solution is 100 ml. How many milliliters is it? It is 100 ml. We are going to make it 100 ml. Now, what I will do is I will transfer it. Guys, help me with a glass rod so that none of the moles of water should fall. Now, what I am doing is I am transferring the liquid slowly. That's why I dissolved it in 50 ml. I did not dissolve it in 100 ml. Now, what I will do is I will wash it 2 to 3 times. Why am I washing it? Because there are particles around the beaker. I will wash it one more time. So, guys, You have to wash it 2 to 3 times. with liquid so that all the moles of oxalic acid be transferred Now, guys, what we have to do is So, guys, you can see That I have filled the liquid up to here. As soon as I fill the liquid up to this line, The 100 ml solution will be ready. But, guys, don't fill it completely. If you fill it completely, then it is possible that After filling it up to here, leave it. You have to fill it in such a way so that none of the liquid goes above this line. So, what I will do is I will fill it in very well. Now, the liquid has reached up to this line You can see that the liquid has reached up to this line. There is a line here and the liquid has reached up to this line. Now, the 100 ml solution is ready. The liquid solution will be filled in here. You have to carefully Shake it twice. What happens when you do this? The extra water that you added will also dissolve with the molecules. Now, the 100 ml stock solution It is ready. The 100 ml stock solution is ready. If you read in your procedure, Then all these things are applied there. So, guys, you must have seen the standard measuring flask has a label. There is a line there. If you fill the solution up to there, Then your 100 ml is ready. So, in the same way, We prepare 0.1 molar standard oxalic acid solution in 100 ml solution So, thank you for watching this video And please subscribe to this channel.