How do you prepare a solution with a specific concentration?

To prepare a solution with a specific concentration, you need to dissolve a precise amount of solute in a specific volume of solvent.

Firstly, you need to understand the concept of molarity, which is the measure of concentration of a solution. It is defined as the number of moles of solute per litre of solution. The formula for molarity is M = moles of solute / litres of solution.

To prepare a solution of a specific concentration, you need to calculate the amount of solute needed using the molarity formula. For example, if you want to prepare 1 litre of a 1M solution of sodium chloride (NaCl), you would need 1 mole of NaCl. As the molar mass of NaCl is approximately 58.44 g/mol, you would need to weigh out 58.44g of NaCl.

Once you have the correct amount of solute, you then need to add it to the solvent. The solvent is usually water, but it can be any liquid in which the solute can dissolve. You should add the solute to a volumetric flask, which allows for precise measurement of the volume of the solution. After adding the solute, you then add the solvent up to the desired volume mark on the flask.

It's important to remember to add the solute first, and then the solvent. This is because if you add the solvent first, you may end up with a solution that is more dilute than intended.

Finally, you should thoroughly mix the solution to ensure that the solute is fully dissolved. This can be done by shaking or stirring the solution. Once the solute is fully dissolved, you have a solution of the desired concentration.

Remember, safety is paramount when handling chemicals. Always wear appropriate protective equipment and work in a well-ventilated area.