What is the weight of a specimen (MW=56.1) in grams if the molarity of a 500 mL solution is 1.5 M?

Answer 1

Molarity means moles solute / liter solution

Liters of solution = 500 ml x 1 L / 1000 ml = 0.500 liters

1.5 M means 1.5 moles / L

moles solute present = 1.5 mols / L x 0.500 L = 0.75 moles

Mass of specimen = 0.75 moles x 56.1 g / mol = 42 g (2 sig. figs.)