Joy is preparing 13 liters of a 20% saline solution. She only has 30% and 10% solution in her lab. How many liters of the 30% and how many liters of the 10% should she mix to make the 20% solution?

1 Answer
Aug 8, 2018

Answer:

The volume of #30%# solution is #=6.5L# and volume of #10%# solution is #=6.5L#

Explanation:

Make a material balance with respect to the saline solution

Let the volume of #30%#solution be #=vL#

Then,

The volume of #10%# solution is #=(13-v)L#

So,

#v*30/100+(13-v)*10/100=13*20/100#

Solving this equation for #v#

#30v+(13-v)*10=13*20#

#30v+130-10v=260#

#20v=130#

#v=130/20=6.5L#

The volume of #30%# solution is #=6.5L# and volume of #10%# solution is #=6.5L#