It is not possible to say whether a colorless watery solution is dilute or concentrated by taking a look at it. But in case of colored solutions of different concentration level, it is possible to say which one is dilute and which one is concentrated by looking at them, just like the way we can differentiate concentration and dilute dal (note that, dal is not a solution but a heterogeneous solution). Now we will see how we can differentiate between concentrated and diluted colored solution.
Task: To make colored watery solutions of different concentrations and to differentiate between concentrated and dilute solutions.
Required accessories: Three test tubes, test tube holder, measuring flask, spoon, copper sulphate and water.
Procedure: Take three clean test tubes. Now place the test tubes in a test tube holder one after another. Take 5 milliliters of water in each tube using a measuring flask. Now add in the first test tube 1 spoon, in the second test tube 2 spoon and in the other 3 spoon of copper sulphate. Then shake the test tubes well till the grains of copper sulphate are completely dissolved. Again set the test tubes in the test tube holder at their own places before.
Analysis: Do all the solutions look the same blue? No, they do not. The solution looks less blue in which you added less copper sulphate. That means it is less dilute solution. In this way, as you increase the amount of copper sulphate, the color of the solutions gradually become deeper. That Main, the solution has become more concentrated from diluted with the increase in the amount of copper sulphate. You can now differentiate between dilute and concentrated solutions by preparing a solution of potassium permanganate and potassium dichromate in the same method.