Question

When 15 g of NaCl is dissolved in water to a final volume of 500 mL the concentration of the solution is 500 mM. What is the molecular weight of NaCl?

Answer 1

sub in: \(\sf moles =\dfrac{mass}{Molar~mass}\)


into: \(\sf Molarity=\dfrac{moles}{L_{solution}}\)



\(\rightarrow \sf Molarity=\dfrac{\dfrac{mass}{Molar~mass}}{L_{solution}}=\dfrac{mass}{Molar~ mass*L_{solution}}\)


solve for molar mass