SOLUTION: A chemistry experiment 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%. How many liter

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Question 1132751: A chemistry experiment 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%.
How many liters of each should be mixed to give the acid needed for the experiment?
How many liters should be mixed to give two liters at a 15% concentration?
Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
x milliliter of 35% sulfuric acid
1000-x milliliters of 10% sulfuric acid

35x%2B10%281000-x%29=15%2A1000

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Here is an alternative to the traditional algebraic method for solving problems like this involving a mixture of two ingredients.

The desired concentration is 15%; the two ingredients are 10% and 35%.

Think of starting with some amount of the 10% and adding the 35%, stopping when the desired 15% concentration is achieved. The question then is when to stop adding the higher concentration acid.

(1) 15% is 1/5 of the way from 10% to 35%. (15%-10% = 5%; 35%-10% = 25%; 5/25 = 1/5)

(2) That means 1/5 of the mixture needs to be the 35% ingredient.

ANSWER: 1/5 of the liter is the 35% acid; the other 4/5 of the liter is the 10% acid.