Describe how to prepare 1 L of a 0.5 M solution of cobalt chloride hexahydrate (CoCl2 6H2O). Be sure to identify the labware shown above, explain your reasoning, and show any calculations.

In chemistry, if you want to express the amount of a substance out of the total amount, you express it in concentration. There are numerous units of measurement: molarity, molality, normality, mass percentages, volume percentage, or a mix of both. For this problem, the unit used for concentration is molarity, denoted by the unit M. It is the amount of moles of solute per liter of solution. If you want to male 1 L of 0.5 M solution, you would need:

Amount of Substance = (0.5 mol/L) * (1 L) = 0.5 moles CoCl₂·6H₂ O

You cannot directly measure 0.5 moles of CoCl₂·6H₂O. You have to convert this into mass units of grams. The molar mass of CoCl₂·6H₂O is equal to 235.83 g/mol

Amount of Substance = (0.5 moles CoCl₂·6H₂O) * (235.83 g/mol)

Amount of Substance = 117.915 g CoCl₂·6H₂O

So, here is how you prepare 1 L of 0.5 M CoCl₂·6H₂O. Collect 117.915 g of CoCl₂·6H₂O crystals by weighing it in an analytical weighing balance. After, place this inside a 1-L volumetric flask. Dilute it with distilled water up to the 1-L mark. The resulting solution is 0.5 M in concentration