What mass, in grams,

Question

What mass, in grams, of sodium chloride is required to make 250.0 ml of 0.1530 M solution?

Answer 1

Start with the basic "mathematical expression".  Yes, yes.  I know that some mathematicians would say that a relationship formed by units is not a mathematical expression, but it'll do.

.

Molarity = moles / liters

solve for moles

moles = molarity x liters

moles = 0.1530 mol / L x 0.250 L = 0.03825 mol

Then convert to the mass of NaCl

0.03825 mol NaCl x (58.5 g NaCl x 1 mol NaCl) = 2.238 grams NaCl

Answer 2

0.250L x 0.1530 mol/L x 58.44g/mol = 2.235g

Answer 3

by definition M = mole / liter soln

Molecular wt of NaCl = 54.45 g / moles

therefore mass of sodium chloride =

( 0.1530 moles / liter ) ( 0.250 L ) ( 58.45 g / moles ) = 2.24 g NaCl