How many liters of each should be mixed to give the acid needed for the experiment if it calls for one liter of sulfuric acid at a 15% concentration, but the supply room only stocks sulfuric acid in concentrations of 10% and 35%?

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Answer 1 · 2014-12-10T16:02:23

Let #X# be the amount of 10% sulfuric acid that is required
Let #Y# be the amount of 35% sulfuric acid that is required

Since the resulting 15% sulfuric acid should be 1 L,

#Y = 1 - X#

Equate the amount of pure sulfuric acid resulting from the parts and from the whole

#0.10X + 0.35(1 - X) = 0.15(1)#

#=> 100 [0.10X + 0.35(1 - X) = 0.15(1)]#

#=> 10X + 35(1 - X) = 15(1)#

#=> 10X + 35 - 35X = 15#

#=> -25X = 15 - 35#

#=> -25X = - 20#

#=> X = 20/25#

#=> X = 0.80#

#Y = 1 - X#

#=> Y = 1 - 0.80#

#=> Y = 0.20#

0.80 L of 10% Sulfuric Acid and 0.20 L of 35% Sulfuric Acid is required