Beakers are suitable for mixing solutions because they have large open tops into which one can pour solvent or large amounts of dry chemicals. Flasks are a bit easier to handle than beakers are, and the solution is less likely to splash out of a flask. The narrow opening discourages evaporative loss and contamination from the outside. A powder funnel can be used to add dry chemicals to a flask, while a glass funnel can be used to add liquid. To measure liquid volumes of 10 milliters or more, graduated cylinders usually are the practical choice. Cylinders are accurate to perhaps 1% of total volume, which is more than sufficient for most solutions. We seldom need volumetric flasks in biology, since we don't need such a high level of precision.

It is good practice to choose graduated cylinders and containers that are as close as possible to the intended volume of the contents. For example, it is not very accurate to use a 2 liter cylinder to measure out 100 ml of water. The same principle holds for weighing materials. It does not make sense to weigh out one hundredth of a gram of substance in a container that weighs 100 grams.

A magnetic stirring rod is useful when it takes some time for a solute to go into solution, although it is possible to add additional contamination into the solution. Use heat only if a formula calls for it.

To create a stock solution, first define clearly what you want to do.  For example, suppose you have 500 ml of a stock solution of sucrose at 325 mM concentration.  Then suppose you need to dilute it to 200 mM.  First, make sure all the units agree.  On other words, the units used for concentration must be the same on both sides of the equation, as must be the units used for volume.

Now you can set up the problem. The total amount of solute is given by the concentration of the solute times the volume of the solution, or C₁V₁. You have 0.5 liter times 0.325 moles/liter, which is 0.1625 moles. To dilute the solution means to increase its volume, obviously, by adding more solvent but no more solute. You know the final desired concentration, namely 200 mM, but you don't know the final volume yet. We'll call it V₂. You know that V₂ times the final concentration, 0.2 moles/liter, has to be 0.1626 moles. The final volume, then, is given by the equation

V₂ = (0.5)(0.325)/0.2

The equation yields 0.8125 L, which is 812.5 ml. You already have 500 ml, so you must add 312 ml to that solution, or simply bring the final volume to 812 ml in a graduated cylinder.