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How many milliliters of pure water must a nurse mix with 450ml of a 6% saline solution to lower the solution to 5% saline?
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There are 0.06*450 = 27 grams of dissolved salt in the original mixture.
This amount of salt does not change, when we add water to the mixture.
So, the new volume V must satisfy = 0.05 grams/mL, or V = = 540 milliliters.
It means that 540 ml - 450 mL = 90 mL of water must be added. ANSWER
Solved.
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It is a standard and typical mixture problem.
In this site, there is a bunch of lessons, covering various types of mixture problems. See introductory lessons
- Mixture problems
- More Mixture problems
- Solving typical word problems on mixtures for solutions
- Word problems on mixtures for antifreeze solutions
- Word problems on mixtures for alloys
- Typical word problems on mixtures from the archive
Read them and become an expert in solution the mixture word problems.
Specifically on DILUTION, see the lesson
- Special type mixture problems on DILUTION adding water
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Mixture problems".
Save the link to this online textbook together with its description
Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson
to your archive and use it when it is needed.