Experiment -1

Name of the experiment: Preparation of standard solution.

Some Basic Definitions :

Solution: A Solution is Homogeneous mixture of two or more substance on molecular level.

Solute: The Constituent of the mixture in a small amount is called solute.

Solvent: The Constituent of the mixture present in a large amount is called the solvent.

Standard Solution: Standard solution is that solution which contains a known weight of the reagent in a definite volume of solution. Or Solution of a known concentration is called a standard solution.

Solution_Solvent_Solute__-_Definition_and_Difference(360p).mp4

Molarity (M) is defined as the number of moles of solute per liter of solution.

Molarity = moles of solute/liters of solution

Normality (N) is defined as the number of mole equivalents per liter of solution:

Normality = number of mole equivalents/1 L of solution

Molality (m) is defined as the number of moles of solute per kilogram of solvent.

Molality = moles of solute/kilograms of solvent

Principle:

Standard solutions are those solutions which contains known weight of reagent in a definite volume of solution. Most of the standard solutions are prepared by dissolving weight amount of solid and adding sufficient water to make the desired volume. We must determine how much solid to weight out to prepare a given volume of solution of a given strength.

Apparatus and Chemical:

1.Digital balance, wash bottle, Distilled water, Sodium Carbonate (Na₂CO₃), Volumetric flask etc.

Preparation of Sodium Carbonate (Na₂CO₃):

I wanted to prepare 100ml of 0.1N Solution. So, we Calculate the concentration like this way.

Molecular weight of Na₂CO₃ = 23*2+12+16*3 =106

Equivalent weight of Na₂CO₃ = 106/2 = 53

So In 1000ml of 1N Na₂CO₃present = 53g

1 1N =53/1000g

100 0.1N =(53*100*0.1)/1000g = 0.53 g

Concentration of Na₂CO₃ = wt. taken /wt. to be taken X desired conc.

= 0.53 / 0.53 X 0.1 N

= 0.1 N

Working Procedure :

1. At first taken weight out 1.325g of Na₂CO₃ with the help of a digital balance.

2. The Volumetric flask cleaned with distilled water.

3. placed the funnel on the top of the Volumetric flask and then into weighted amount of Na₂CO_3.

4. slowly run the Distilled water over the funnel and shake the flak until mixed properly.

5.Finally the Distilled water was poured in to the flask up to the mark to make a 250ml solution

Preperation of standard soiution

Result:

The exact concentration of preparation of the Na₂CO₃ solution is 0.1N.

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