What mass of water is necessary to prepare 270.0g of .800% saline solution?

Answer 1

Hey Isabel. Thanks for your question.

In order to produce 270 g of 0.8% saline solution (NaCl dissolved in water), NaCl must make up 0.8% of the total weight:

270 g x 0.008 = 2.16 g (Since it's a 0.8% solution, 0.8 needs to be divided by 100 to give us a number to multiply)

If we have 2.16 g of NaCl in the solution, the rest must be water:

270 g - 2.16 g = 267.84 g of water.

Hope this helps!

Answer 2

0.800% saline (m/m) means 0.800 g NaCl per 100 g solution

0.800 g NaCl/100 g x 270 g solution = 2.16 g NaCl

100 g solution - 2.16 g NaCl = 97.84 g water needed

Looking at this problem another way...

270.0 g x 0.8% NaCl = 2.16 g NaCl

100 g soln - 2.16 g NaCl = 97.84 g water