Calculate the mass of sodium chloride required to prepare 500 cm³ of a 0.9% (w/v) saline solution for use as an intravenous fluid. - Leaving Cert Chemistry - Question 1 - 2017

A 0.9% (w/v) saline solution means that there are 0.9 grams of sodium chloride (NaCl) in 100 cm³ of solution. To find the mass required for 500 cm³, we can set up a simple proportion:

If 0.9 g is to 100 cm³, then how many grams (x) is to 500 cm³?

Using the formula:

x = rac{0.9 ext{ g}}{100 ext{ cm}^3} imes 500 ext{ cm}^3

Calculating this gives:

x = rac{0.9 imes 500}{100} = 4.5 ext{ g}

Therefore, the mass of sodium chloride required is 4.5 g.