Question

an empty 3.5 L container weighs 650 g when empty. When filled with a 3.5%, by mass, of salt solution, the total mass then is 3.375 kg. How many grams of salt are there in the solution in the container?

Answer 1

3375g = mass container + salt soln
-650g = mass empty container
-----------------
2725g = mass salt soln.

3.5% w/w means 3.5 g NaCl/100 g soln; therefore,
3.5 x (2725/100) = ??g NaCl in the soln.