How many grams of NaCl (molarmass=58g/mol) are needed to prepare 100.mL of a 0.25M NaCl solution?

Answer 1

Molarity = moles of solute / liters of solution

100 mL = 0.100 L

0.25 M = moles NaCl / 0.100 L

(0.25 M)(0.100 L) = x moles

= 0.025 mols NaCl

Convert this quantity to grams of NaCl

58 g / mol * 0.025 mols = 1.45 g NaCl needed