ChemCollective-Virtual-Labs/C2/Density-of-Solids-and-Liquids/English-timed
| Time | Narration |
| 00:01 | Welcome to this tutorial on Density of Metals and Liquids using Vlabs. |
| 00:08 | In this tutorial, we will learn to determine, Densities of Metals and liquids. |
| 00:14 | To follow this tutorial you should be familiar with, ChemCollective Vlabs interface.
If not, for relevant tutorials please visit our website. |
| 00:26 | Here I am using, Mac OS version 10.10.5
ChemCollective Vlabs version 2.1.0 |
| 00:36 | Java version 8. |
| 00:39 | Here I have opened a Vlabs window. |
| 00:43 | Click on File menu and select Load homework option. |
| 00:48 | Select Molarity and Density from the list. |
| 00:52 | Double-click on Metals Density Problem from the sub-menu. |
| 00:57 | Go to Problem description in the Stockroom explorer. |
| 01:02 | Pause the video to read the problem and then resume again. |
| 01:07 | Problem states that you have 3 unlabeled bottles with metallic powder.
You need to identify the metals in the bottles. |
| 01:17 | The metal densities are given in the problem description.
We will use Archimedes' Principle to find the densities of metals. |
| 01:28 | An object when immersed in water will displace water.
The displaced water will be equal to its volume. |
| 01:38 | Different metals have different densities.
Hence, different metals of the same weight have different volumes. |
| 01:47 | A metal that is less dense will displace more water than a denser one. |
| 01:53 | Switch to Workbench |
| 01:56 | Double Click on Metal 1, Metal 2, Metal 3 to add them to the Workbench.
Double click on water icon. |
| 02:06 | Click on Glassware icon.
Select Graduated Cylinders. |
| 02:12 | From the sub-menu select 25 ml Graduated Cylinder. |
| 02:17 | We need three 25 ml Graduated Cylinders for this experiment. |
| 02:23 | Right-click on Graduated Cylinder. |
| 02:26 | Context menu opens.
Using Duplicate option make 2 copies of the Graduated Cylinder. |
| 02:34 | Drag and bring the Graduated Cylinders to the centre of the Workbench. |
| 02:41 | Label the Cylinders as 1, 2 and 3. |
| 02:49 | Let us drag graduated cylinder 1 to the water tank. |
| 02:54 | Notice that a red warning icon appears. |
| 02:58 | This indicates that procedure is incorrect.
Place graduated cylinder 1 aside. |
| 03:06 | The correct procedure is to drag water on to the graduated cylinder. |
| 03:12 | Change the transfer mode to Precise Transfer using Tools menu. |
| 03:17 | Type 10 in the Transfer amount input bar.
Click on pour. |
| 03:23 | 10 ml of water is transferred into the graduated cylinder 1. |
| 03:29 | Likewise transfer 10ml of water into graduated cylinders 2 and 3. |
| 03:37 | Move the water tank to a different place on the Workbench. |
| 03:41 | Click on Select Tools menu, from the list, select Scale. |
| 03:47 | Drag the Scale to a convenient position on the Workbench. |
| 03:51 | Again click on Select Tools menu, from the list select Weighing Boat. |
| 03:57 | We need three Weighing Boats for this experiment.
We can also use short-cut keys, to copy and paste. |
| 04:06 | Click on Weighing Boat.
Use Ctrl-C to copy and Ctrl-V to paste. |
| 04:13 | Drag and bring the weighing boats to the centre of the Workbench |
| 04:19 | Label the Weighing Boats as 1, 2 and 3. |
| 04:24 | Place weighing boat 1 over the scale.
Click on TARE button on the scale. |
| 04:31 | Drag Metal 1 over to weighing boat 1. |
| 04:36 | Type 50 in the Transfer Amount(g) input bar
Click on Pour. Place the bottle aside. |
| 04:44 | Remove the weighing boat from the scale.
Place weighing boat 1 over the graduated cylinder 1. |
| 04:52 | Type 50 in the Transfer Amount input bar .
Click on Pour. |
| 04:58 | Observe the level of water in the graduated cylinder.
It has risen by 5 ml. |
| 05:06 | Keep the weighing boat 1 aside. |
| 05:09 | Now, Place weighing boat 2 on the scale.
Click on TARE button on the scale. |
| 05:16 | Drag Metal 2 over weighing boat 2. |
| 05:20 | Type 50 in the Transfer Amount(g) input bar.
Click on Pour. |
| 05:26 | Place the bottle aside. |
| 05:28 | Remove the weighing boat 2 from the scale.
Place weighing boat 2 over the graduated cylinder 2. |
| 05:36 | Type 50 in the Transfer Amount(g)input bar.
Click on Pour. |
| 05:42 | Observe that the water level in the cylinder has risen by 4 ml.
Keep the weighing boat 2 aside. |
| 05:51 | Similarly, weigh 50 grams of metal 3 using weighing boat 3. |
| 06:00 | Place weighing boat 3 over the graduated cylinder. |
| 06:04 | Type 50 in the Transfer Amount(g) input bar.
Click on Pour. |
| 06:10 | Water level in the cylinder has risen by 2.5 ml.
Keep the weighing boat 3 aside. |
| 06:18 | This slide shows the density calculations for the metals.
Calculate the densities using the formula: Density= mass/volume. |
| 06:29 | Experimental density of Metal 1 is 10 which corresponds to Silver. |
| 06:35 | Metal 2 is 12.2 which corresponds to Rhodium. |
| 06:40 | Metal 3 is 20 which corresponds to Platinum. |
| 06:45 | Repeat the above experiment with different metal weights (30 g and 40 g).
Tabulate and analyse your results. |
| 06:56 | Lets proceed to the liquid density problem. |
| 07:00 | Let us add a new workbench.
Click on File and select New workbench option. |
| 07:08 | Click on the workbench. |
| 07:10 | Go to File menu and select Load homework option. |
| 07:14 | Select Molarity and Density from the list. |
| 07:18 | Double-click on Liquid density problem. |
| 07:22 | Double-click on problem description in the stockroom explorer. |
| 07:27 | Pause the video to read the problem statement.
Resume after reading. |
| 07:33 | The problem states that there are two compounds of A-1 and A-2. |
| 07:38 | One of the liquids is a preservative, other liquid is not a preservative.
The preservative has higher density. |
| 07:48 | Our aim is to find the liquid containing Preservative.
For this we need to measure densities of A-1 and A-2. |
| 07:58 | Switch back to Workbench |
| 08:02 | Double-click on compounds A-1 and A-2 to add them to Workbench. |
| 08:08 | Obtain a 100ml volumetric flask from the glassware option. |
| 08:14 | We need two 100ml volumetric flasks for this experiment. |
| 08:20 | We can make a copy using Duplicate option. |
| 08:24 | Drag and bring the flasks to the center of the workbench. |
| 08:30 | Label the flasks as A-1 and A-2.
We can rename by pressing F2. |
| 08:39 | Click on Select tools icon.
Select Scale and add it to the Workbench. |
| 08:46 | Place the volumetric flask A-1 on the scale.
Click on TARE button. |
| 08:52 | Transfer 100ml of Compound A1 to flask A-1 by Precise Transfer mode. |
| 09:01 | Note the mass from the scale.
Scale reads 126 g. |
| 09:08 | Note this value. Place the flask A-1 aside. |
| 09:13 | Remove Volumetric flask from the scale. |
| 09:17 | Next place flask A-2 on the scale, click on TARE.
Pour 100 ml of Compound A-2. |
| 09:29 | Scale reads 85 g.
Note this value. |
| 09:35 | Experimental results are tabulated on this slide.
Calculate densities using the formula: Density=mass/volume |
| 09:47 | Observe that density of Compound A-1 is more than Compound A-2.
Therefore Compound A-1 contains the preservative. |
| 09:57 | Let's summarize.
In this tutorial we have learnt to measure, Densities of silver, rhodium and platinum using Archimedes' Principle. |
| 10:09 | Densities of liquids with unknown concentration. |
| 10:14 | For the assignment.
Open default lab setup window. |
| 10:19 | You will find many stock solutions.
Find density for a few solutions of your choice. |
| 10:28 | The video at the following link summarizes the Spoken Tutorial project.
Please download and watch it. |
| 10:35 | The Spoken Tutorial Project team: conducts workshops using spoken tutorials and
gives certificates on passing online tests. For more details, please write to us. |
| 10:48 | Please post your timed queries in this forum. |
| 10:52 | Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
More information on this mission is available at this link. |
| 11:03 | This tutorial is contributed by Snehalatha Kaliappan and Madhuri Ganapathi from IIT-Bombay.
Thank you for joining |
