SOLUTION: To generate hydrogen in a chemical lab, a 40% solution of Sulphuric acid is needed. You have 50ml of an 86% solution of sulphuric acid. How many ml of water should be added to dilu

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Question 159478: To generate hydrogen in a chemical lab, a 40% solution of Sulphuric acid is needed. You have 50ml of an 86% solution of sulphuric acid. How many ml of water should be added to dilute the solution to the required 40% sulphuric acid?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
In words:
(ml of acid in 86% solution)/(ml of 86% solution + added water) = 40%
Let h= the ml of water to be added
The ml of sulphuric acid in 50 ml of 86% solution is:
.86%2A50+=+43ml
43+%2F+%2850+%2B+h%29+=+.4
Multiply both sides by 50+%2B+h
43+=+.4%2A%2850+%2B+h%29
43+=+20+%2B+.4h
.4h+=+23
h+=+57.5ml
57.5 ml of water must be added to get a 40% solution
check:
43+%2F+%2850+%2B+h%29+=+.4
43+%2F+%2850+%2B+57.5%29+=+.4
43+%2F+107.5+=+.4
.4+=+.4
OK