What is the mass of table salt and what volume of water is required to prepare a 5% solution with a mass of 120 g?

The mass fraction of NaCl in the solution is determined by the formula w (NaCl) = m (NaCl) / m solution. Hence m (NaCl) = w (NaCl) * m solution. m (NaCl) = 0.05 * 120g = 6g. We calculate the mass of water
m (H2O) = m solution-m (NaCl) = 120g-6g = 114g. The volume of water is V (H2O) = m (H2O) / p (H2O), where p is the density of the water. We consider the density of water equal to 1 g / cm3, then V (H2O) = 114/1 = 114 cm3. Answer: 6g NaCl and 114ml of water are required.