Question

9. Forensic chemists use Super Glue to help them see fingerprints left behind at crime scenes. If cyanoacrylate, the main component of Super Glue B, is vaporized, it will be attracted to the oils left behind after someone touches an object. Forensic investigators will then rinse the print with a solution of europium chloride hexahydrate, EuCl3-6 H20, which fluoresces when exposed to ultraviolet light. If 0.625 g of europium chloride hexahydrate is dissolved in enough water to make 500.0 mL of solution, what is the molarity of the solution?

Answer 1

Molecular weight of europium chloride hexahydrate is 366.41 g/mol.

0.625 g=0.625/366.41 moles= 0.0017 moles

Concentration=moles/volume in L. 500 mL=0.5 L

=0.0017/0.5 L=0.0034 M solution