ChemCollective-Virtual-Labs/C2/Preparation-of-Standard-Solutions/English-timed
| Time | Narration |
| 00:01 | Welcome to this spoken tutorial on Preparation of Standard Solutions. |
| 00:07 | In this tutorial, we will learn to prepare standard solution of: 1 molar sodium chloride |
| 00:14 | To follow this tutorial you should be familiar with, Higher secondary school Chemistry. |
| 00:21 | Here I am using
Mac OS version 10.10.5 |
| 00:26 | ChemCollective Vlabs version 2.1.0 |
| 00:31 | Java version 8.0
To run this application smoothly, please install latest version of Java. |
| 00:41 | Here I have opened Virtual Chemistry labs application window. |
| 00:46 | We will begin by preparing standard solutions from solids. |
| 00:51 | Go to File menu and select Load Homework option. |
| 00:56 | Default Lab Setup dialogue box opens. |
| 01:00 | The dialogue box lists a number of Local Problems.
From the list, double-click to select Molarity and Density. |
| 01:10 | From the sub menu, double-click on Making solutions from solids. |
| 01:16 | On the left panel, Stockroom explorer opens.
It displays the required solutions and the problem description. |
| 01:26 | Double-click on problem description icon. |
| 01:30 | A problem description window opens next to the Workbench. |
| 01:35 | Window briefly describes list of problems you need to solve. |
| 01:40 | Let's start with the first problem. |
| 01:43 | We need to prepare 100 ml of 1 molar Sodium Chloride solution. |
| 01:49 | Switch back to the Workbench by clicking on Workbench tab. |
| 01:54 | On the right-side panel, Stockroom Explorer opens.
It lists various chemicals to be used for this experiment. |
| 02:04 | It has distilled water for making solutions. |
| 02:08 | Some solids such as Sodium Chloride, Magnesium Chloride and Sodium Sulphate. |
| 02:15 | Let us place the required chemicals and apparatus on the Workbench. |
| 02:20 | Double-Click on Sodium chloride and Distilled water icons. |
| 02:26 | Sodium Chloride bottle and Distilled water are added to the Workbench. |
| 02:32 | Click on Click to select tools from the drop down menu, Click on Scale. |
| 02:39 | Scale appears on the work bench. |
| 02:42 | Go to Click to select new glassware from the drop down menu icon. |
| 02:48 | Select Erlenmeyers. From the sub menu, select 250 ml Erlenmeyer Flask. |
| 02:57 | Go to Select new glassware icon. |
| 03:00 | Select Volumetrics. |
| 03:03 | From the sub menu, select 100ml Volumetric Flask. |
| 03:08 | Again click on Select new glassware icon.
Select Pipets. |
| 03:14 | From the sub menu, select 5ml Pipet. |
| 03:19 | Molar mass of sodium chloride is 58.44 g/mol.
Use the given formula to calculate Molarity. |
| 03:30 | For 100ml of 1 M(molar) solution we need 5.844 grams of Sodium Chloride. |
| 03:39 | Back to the workbench.
Drag the Scale to a convenient position on the Workbench. |
| 03:45 | Click on Erlenmeyer Flask and drag on to the Scale. |
| 03:50 | Release the mouse button after you see a green plus mark. |
| 03:55 | Green plus mark indicates suitable position for placing the Erlenmeyer Flask. |
| 04:02 | Release the mouse button, to place the Erlenmeyer Flask on the Scale.
Scale shows mass of the Erlenmeyer Flask. |
| 04:11 | Click on TARE button on the Scale.
This step will reset the weight value to zero. |
| 04:18 | Scale reads 0 g(zero grams). |
| 04:21 | Click on Sodium Chloride bottle and move it over the Erlenmeyer Flask. |
| 04:27 | Place the bottle in the correct position after it shows green plus mark. |
| 04:33 | Type 5.844 in the Transfer amount text bar at the bottom of the Workbench.
Click on Pour button. |
| 04:44 | You can see that the Scale reads exactly 5.844 grams. |
| 04:51 | Click and drag Sodium Chloride bottle to a different place on the Workbench. |
| 04:57 | Remove the Erlenmeyer Flask and keep it aside. |
| 05:01 | To remove the Scale from the Workbench, Click on the Scale and press Delete. |
| 05:07 | Drag the Distilled water on to the 250ml Erlenmeyer Flask. |
| 05:12 | Type 90 in the Transfer bar below.
Click on Pour. |
| 05:18 | This will transfer 90 ml of distilled water into the Flask. |
| 05:23 | Drag and place the distilled water to a corner of the Workbench. |
| 05:28 | Place the volumetric flask next to Erlenmeyer flask. |
| 05:33 | Click and drag the Erlenmeyer on to 100ml Volumetric Flask.
Make sure that green plus mark appears. |
| 05:42 | To transfer the contents of the Flask, use Realistic Transfer option. |
| 05:47 | Click on Tools menu.
Scroll down and click on Transfer Bar. |
| 05:53 | From the sub menu click on Realistic Transfer radio button. |
| 05:58 | Realistic transfer Scale appears at the bottom of the Workbench. |
| 06:03 | Click on Pour button.
Hold the left mouse button until entire amount has been transferred to the Flask. |
| 06:12 | To wash the Erlenmeyer Flask with distilled water; Place the water tank over the Erlenmeyer Flask and transfer 5ml distilled water. |
| 06:23 | Change the Transfer Bar to Precise Transfer using Tools menu.
Type 5 in the Transfer bar below. |
| 06:30 | Click on Pour button. |
| 06:34 | Now pour the contents of the Erlenmeyer Flask into the Volumetric Flask. |
| 06:40 | To transfer the contents of the Flask, use Realistic Transfer option. |
| 06:48 | Click on Pour button.
Hold the left mouse button until entire amount has been transferred to the Flask. |
| 06:58 | Change the transfer mode to Precise Transfer.
Place the distilled water above the Erlenmeyer Flask. |
| 07:07 | Transfer 5 ml distilled water into Erlenmeyer Flask. |
| 07:13 | Type 5 in the Transfer amount text bar and click on Pour. |
| 07:19 | Move the distilled water to a corner of the Workbench. |
| 07:23 | Move the 5 ml Pipet onto Erlenmeyer Flask. |
| 07:28 | Type 5 in the Transfer amount text bar and click on Withdraw. |
| 07:34 | 5 ml of water is withdrawn into the Pipet. |
| 07:39 | Drag the Pipet onto 100 mL Volumetric Flask. |
| 07:44 | Change the transfer mode to Realistic Transfer using Tools menu. |
| 07:49 | Click on Pour button gradually so as to make up to the mark. |
| 07:55 | For colourless solutions, the lower meniscus must be on the 100 ml mark. |
| 08:03 | Click on the standard Flask.
We now have 100 mL of sodium chloride(NaCl) solution as indicated in the Solution info panel. |
| 08:14 | Click on the standard Flask.
Solution Info Panel on the right displays the Species and the corresponding Molarity. |
| 08:24 | Observe that the concentration of sodium cation is approximately 1.0 molar. |
| 08:30 | Go back to Problem description window.
Similarly you can also try some of these problems. |
| 08:39 | Let us summarize.
In this tutorial we have learnt to prepare, 100 ml of 1 molar sodium chloride solution. |
| 08:48 | As an assignment, Prepare the following standard solutions.
250 ml of 5 molar sodium chloride solution 500 ml of 10 normal Magnesium chloride solution. |
| 09:02 | The video at the following link summarizes the Spoken Tutorial project.
Please download and watch it. |
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| 09:23 | Do you have questions in THIS Spoken Tutorial?
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| 10:07 | This tutorial is contributed by Snehalatha Kaliappan and Madhuri Ganapathi from IIT-Bombay.
Thank you for joining. |
