When a chemist dilutes pure acid with another substance, the resulting mixture is no longer pure acid. Consistent with the words, pure acid is 100% acid. So, there are 20 grams of pure acid in 20 grams of a pure-acid solution. Laura, a chemist, has 20 grams of a solution that is only 40% acid. How many grams of pure acid are there in Laura´s acid solution?
naturally, that would be 0.40 * 20, right?
To find the grams of pure acid in Laura's solution, we need to calculate 40% of the total weight of the solution.
Step 1: Calculate the total weight of the solution
Since Laura has 20 grams of a solution that is only 40% acid, the remaining 60% must be another substance. To find the total weight of the solution, we divide the weight by the percentage of actual acid present:
Total weight of solution = 20 grams / 0.4 (40%) = 50 grams
Step 2: Calculate the grams of pure acid in the solution
Since the solution is now 100% and contains 40% acid, we need to find 40% of 50 grams:
Grams of pure acid = 40% (0.4) * 50 grams = 20 grams
Therefore, there are 20 grams of pure acid in Laura's acid solution.