Question

how many grams of NaCl are needed to prepare a solution of 500 mL if it's Molarity has to be 0.20

Answer 1

Molarity= number of moles/ volume in L

0.20 M= number of moles/ 0.5 L

Number of moles= 0.2 M* 0.5 L = 0.1 moles

Mass of NaCl= number of moles* molar mass

Mass of NaCl= 0.1 mol* 58.5 g. Mol^-1 = 5.85 g