Biology Question

Question

How many grams of NaCl would you dissolve in water to make a 500 mM NaCl solution with 1-liter final volume ?

Answer 1

Molarity (M) = mole of solute / volume of solution

500 mM = 0.5 M volume of solution = 1 L

mole of solute (NaCl) = MV = 0.5 mole/L x 1 L = 0.5 mole NaCl

mass of NaCl =molar mass of NaCl x mole of NaCl

molar mass of NaCl = 23 + 35.5 = 58.5 g / mole

mass of NaCl = 58.5 g / mole x 0.5 mole = 29.25 g = 29 g NaCl