Alejandro R. answered • 05/24/18

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You can tell that the person who made this question is probably not a chemist! So the

**total volume**of your final mixture is going to be 15 liters + the liters of pure water you are going to add.**15+x.**You want the % of pure water by volume in the end to be 80% (0.8). So you need to set up a fraction

**0.8= (volume of pure water in final mixture)/total volume**

What makes this tricky is that the 80% acid mixture is presumably 20% pure water. So the

**volume of pure water in the final mixture is (15*0.2)+x**instead of just x.**0.8=(3+x)/(15+x)**-->

**x=45 L**