Narration 1 00:00:01 --> 00:00:06 Hello everyone. Welcome to this tutorial on Conductivity of ionic solutions. 2 00:00:07 --> 00:00:14 In this tutorial, we will learnt to:

Measure Conductivity and Calculate the resistance of ionic solutions.

3 00:00:15 --> 00:00:22 Here, I am using:

ExpEYES version 3.1.0 Ubuntu Linux OS version 14.04

4 00:00:23 --> 00:00:34 To follow this tutorial, you should be familiar with ExpEYES Junior interface.

5 00:00:35 --> 00:00:37 Let's first define conductivity of a solution. 6 00:00:38 --> 00:00:43 Conductivity of a solution is a measure of its ability to conduct electricity. 7 00:00:44 --> 00:00:50 Conductivity of water is directly related to the concentration of ions dissolved in it. 8 00:00:51 --> 00:00:55 Now we will demonstrate conductivity of tap water. 9 00:00:56 --> 00:01:01 I will explain the circuit connections. A1 is connected to SINE. 10 00:01:02 --> 00:01:07 Wires from SINE and A2 are dipped in glass tumbler containing tap water. 11 00:01:08 --> 00:01:15 A 10K resistor is connected between A2 and GND. This is the circuit diagram. 12 00:01:16 --> 00:01:19 Let's see the result on the Plot window. 13 00:01:20 --> 00:01:27 On the Plot window, click on A1 and drag to CH1. A1 is assigned to CH1. 14 00:01:28 --> 00:01:34 Click on A2 and drag to CH2.

A2 is assigned to CH2.

15 00:01:35 --> 00:01:42 Move the mSec/div slider to adjust the waves. Two sine waves are generated. 16 00:01:43 --> 00:01:49 Black trace is the original sine wave. Red trace is conductivity of tap water. 17 00:01:50 --> 00:01:55 Click on CH1 and drag to FIT. Click on CH2 and drag to FIT. 18 00:01:56 --> 00:02:07 Observe the voltage and frequency values on the right side of the window. Notice that voltage of tap water is very less compared to the input voltage. 19 00:02:08 --> 00:02:14 Right click on CH1 to see voltages and Phase difference in degree. 20 00:02:15 --> 00:02:26 Now we will measure conductivity of copper sulphate solution. To make the solution, one spatula of copper sulphate is dissolved in 100 ml of water. 21 00:02:27 --> 00:02:33 In the same connection, wires from SINE and A2 are dipped in copper sulphate solution. 22 00:02:34 --> 00:02:37 On the Plot window we can see the conductivity curve. 23 00:02:38 --> 00:02:41 Red trace is conductivity of copper sulphate solution. 24 00:02:42 --> 00:02:47 Increased conductivity is due to copper and sulphate ions present in the solution. 25 00:02:48 --> 00:02:51 Observe the voltage and frequency values on the right. 26 00:02:52 --> 00:02:58 Right click on CH1 to see voltages and Phase difference values. 27 00:02:59 --> 00:03:08 Now, we will measure conductivity of dilute sulphuric acid solution. A few drops of dilute sulphuric acid are added to water. 28 00:03:09 --> 00:03:16 Wires are dipped in sulphuric acid solution. Let's see the result on the Plot window. 29 00:03:17 --> 00:03:22 Observe that black and red traces are almost coinciding with each other. 30 00:03:23 --> 00:03:29 Conductivity of tap water has increased on adding a few drops of dilute sulphuric acid. 31 00:03:30 --> 00:03:33 Observe the voltage and frequency values on the right. 32 00:03:34 --> 00:03:40 Right click on CH1 to see voltages and Phase difference in degree. 33 00:03:41 --> 00:03:51 We will measure conductivity of dilute Potassium hydroxide solution. A few drops of dilute Potassium hydroxide solution are added to tap water. 34 00:03:52 --> 00:03:57 We can see that black and red traces are almost coinciding with each other. 35 00:03:58 --> 00:04:04 Notice the increased conductivity of tap water on adding a few drops of Potassium hydroxide solution. 36 00:04:05 --> 00:04:10 Observe the voltage and frequency values on the right side of the window. 37 00:04:11 --> 00:04:17 Right click on CH1 to see voltages and Phase difference in degree. 38 00:04:18 --> 00:04:26 Using the voltage values we have calculated the resistance of ionic solutions and tabulated the results. 39 00:04:27 --> 00:04:37 Resistance value for tap water is 7.7 KOhm (kilo ohm).

Resistance value for copper sulphate solution is 1.2 KOhm.

40 00:04:38 --> 00:04:54 Sulphuric acid solution is 0.17 KOhm and potassium hydroxide solution is 0.14 KOhm.

Notice that resistance values decreased with the increase in ionic concentration.

41 00:04:55 --> 00:04:56 Let's summarize. 42 00:04:57 --> 00:05:05 In this tutorial, we have learnt to:

Measure Conductivity and Calculate the resistance of ionic solutions.

43 00:05:06 --> 00:05:17 As an assignment,Using sodium hydroxide, acetic acid and sodium chloride solutions measure conductivity and calculate the resistance of ionic solutions. 44 00:05:18 --> 00:05:25 This video summarizes the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it. 45 00:05:26 --> 00:05:31 We conduct workshops using Spoken Tutorials and give certificates. Please contact us. 46 00:05:32 --> 00:05:38 The Spoken Tutorial Project is funded by NMEICT, MHRD Government of India. 47 00:05:39 --> 00:05:44 This tutorial is contributed by Kaushik Datta and Madhuri Ganapathi.Thank you for joining.