Question 1

How do I prepare a molar solution?

Accepted Answer

Calculate mass needed (mass = M × V × molar mass), weigh the solute, dissolve in a small amount of solvent, transfer to a volumetric flask, and add solvent to the desired final volume.

Question 2

Why do I dissolve first then add to volume?

Accepted Answer

Dissolving the solute can change the total volume (due to volume of dissolution). By dissolving first and then bringing to final volume in a volumetric flask, you ensure the exact concentration.

Question 3

What is purity correction?

Accepted Answer

If your solute is not 100% pure (e.g., 95% NaOH), you need to weigh more to account for the impurity. Adjusted mass = pure mass / (purity/100).

Question 4

What is a standard solution?

Accepted Answer

A standard solution is one whose concentration is accurately known. Primary standards (like sodium carbonate or potassium hydrogen phthalate) can be weighed directly. Secondary standards must be standardized by titration.

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