Answer:
To prepare 60 mL of a 19% solution, you will need 11.4 grams of NaCl.
Step-by-step explanation:
Solutions can be considered as formed by two components: a solute (the component in lower proportion) and a solvent (the one in bigger proportion). Sometimes we refer to solution concentration in terms of the percentage of solute respect to that of solution. You can express solution´s concentration in units of precentage mass in volume (% m/v), percentage mass in mass (% m/m) or percentage volume in volume (% v/v), among others. Here the numerator refers to the solute and denominator to solution. All these units are refered to 100 mililiters of solution.
In the present case, the quantity of NaCl (solute) is asked in grams and that of solution is given in mililiters.
19 % m/v = 19 grams of NaCl/100 mililiters of solution. So,
19 grams NaCl ---------------- 100 ml solution
11.4 =x-------------- 60 ml solution.
Finally, to prepare 60 mL of a 19% solution, you will need 11.4 grams of NaCl.