Understand what a mole is and what a molar solution is. A mole is defined as 6.02 x 10^23 molecules of a substance. This odd number was chosen because the amount in grams of 1 mole of a chemical corresponds closely to its atomic weight. For example 1 mole of water weighs about 18 grams and the atomic weight of a water molecule is about 18. A molar solution contains a specified number of moles of a solid per liter of solvent. For convenience, the steps below assume you are making 1 liter of a molar solution.

Know the chemical reactions that may take place when you add the solvent to the solid. Never neglect this step. Combining some chemicals can be extremely dangerous and even fatal if you are exposed to toxic chemicals produced by a reaction. Always use pure chemicals. For example, use distilled rather than tap water. Tap water contains impurities that can alter the chemical behavior of your solution.

Calculate the amount of solid you need to make molar solutions. To do this, multiply the molar weight of the solid by the concentration (number of moles per liter) of the molar solution you want to make. Then use a scale calibrated in grams to measure out this amount of the solid you need.

Place the solid in an empty 1-liter jar. Add the solvent until you have exactly 1 liter. You may need to stir the solution in order to get the solid to dissolve.