What is the meaning of standardization of solution?

Answer 1

Standardizing a solution is done to find the precise concentration of the solution. It is often done through titrations between two different chemicals, usually an acid or a base. Standardizing a solution can also be done if you know the concentration, but just want to double check it.

Answer 2

Preparing a Standard Solution (Part A)

Aim

The purpose of this experiment is to prepare a standard solution of sodium hydrogen sulphate.

Introduction

Sodium hydrogen sulphate NaHSO4 is a primary standard because it meets certain requirements.

1. It must be available in a highly pure state.
2. It must be stable in air.
3. It must be easily soluble in water.
4. It should have a high molar mass.
5. In solution, when used in volumetric analysis, it must undergo complete and rapid reaction.

You weigh accurately a sample of sodium hydrogen sulphate and use it to make a solution of concentration close to 0.20 mol dm-3.

Procedure

1. Transfer between 4.8 and 5.4g of sodium hydrogen sulphate into a weighing bottle and weigh it to the nearest 0.01g.
2. Put about 50cm3 of water into a 250cm3 beaker. Carefully transfer the bulk of the sodium hydrogen sulphate from the weighing bottle into the beaker.
3. Reweigh the bottle with any remaining sodium hydrogen sulphate to the nearest 0.01g.
4. Stir to dissolve the solid, add more water if necessary.
5. Transfer the solution to a volumetric flask through the filter funnel. Rinse the stirring rod and the beaker making sure all the liquid goes into the volumetric flask.
6. Add distilled water until the level is within about 1 cm of the mark on the neck of the flask.
7. Using the dropping pipette add enough water to bring the bottom of the meniscus to the mark. Insert the stopper and shake thoroughly ten times to ensure complete mixing.
8. Label the flask with the contents, your name and the date. Leave a space for the concentration to be filled in after you have calculated it.

Results and Calculations

Fill in the results table below

Molar Mass of Sodium Hydrogen Sulphate

g mol-1

Mass of bottle and contents before transfer

g

Mass of bottle and any remaining contents after transfer

g

Mass of Sodium Hydrogen Sulphate used

g

Amount of Sodium Hydrogen Sulphate

n = m/M

mol

Volume of Solution

dm3

Concentration of Sodium Hydrogen Sulphate

c = n/V

mol dm-3

Using the Standard Solution to find the Unknown Concentration of Sodium Hydroxide (Part B)

Method

1. Using your standard solution prepared earlier clean and then fill a burette with the standard solution.

2. Pipette 25cm3 of a solution of sodium hydroxide into a conical flask sitting on a white tile.

3. Add 3 drops of phenolphthalein indicator and titrate with the standard solution in the burette.

4. Repeat the titration until you have an accurate value for the end point of the titration.

Calculation

1. Sodium hydroxide and Sodium Hydrogen Sulphate react in a 1:1 molar ratio.

2. Calculate the exact concentration of the solution of Sodium Hydrogen Sulphate you made up.

3. Using the value from your titration, calculate the exact concentration of the sodium hydroxide solution.

RESULTS TABLE

Pipette solution

Sodium hydroxide

UNKNOWN mol dm-3

cm3

Burette solution

Sodium Hydrogen Sulphate

mol dm-3

Trial

1

2

3

Burette readings

Final

Initial

Volume used (titre) cm3

Mean titre / cm3

Answer 3

first you have to mix the volumes of the sunstance and yeah basically