The answer is 296.3g.
Saline solution is a mixture of table salt (NaCl) and water (H_2O).
The solution's percent concentration by mass, defined as the mass of solute (in this case, NaCl) divided by the total mass of the solution and multiplied by 100%, is said to be 1.25%.
The total mass of the solution is equal to
m_(solut ion) = m_(NaCl) + m_(water)
Knowing that c% = m_(solute)/(m_(solut ion)) * 100%, and that the
mass of the solution is 300g, we can determine the mass of NaCl by
m_(NaCl) = (c * m_(solut ion))/100 = (1.25 * 300)/100 = 3.75grams
This means that the mass of water is equal to
m_(water) = m_(solut ion) -m_(NaCl) = 300- 3.75 = 296.3 grams, which makes sense since the bulk of this particular solution must be represented by water, given the fact that its percent concentration by mass is 1.25%.
