A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

have a 700ml solution of 30% acid, needs a 50% solution of acid. How many ml of 100% acid should be added?

  • This Question is Closed
  1. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    hmmm ok. so we're saying that the entire solution needs to be .5 (50%)

  2. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so you can solve an equation like this: (.3*700 + 1*x)/(x+700) = .5

  3. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so multiplying both sides by x+700, we get : .5x + 350 = x + 210

  4. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    subtract .5 from both sides, and you get .5x + 210 = 350

  5. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so .5x = 140

  6. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    140/.5 = x = 280

  7. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so I'd say 280ml

  8. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    basically - .5 is the entire fraction of acid in the total solution, hence my equation in the first step - so we know the first part of the end solution since it's given

  9. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    700ml * .3 is pure acid

  10. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    what you add to the solution, is also pure 100% acid, so 1*x

  11. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    the denominator in this case will be the total amount of solution (so the original 700ml plus whatever you added)

  12. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    and we know that the entire thing - the fraction - is .5

  13. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    and following that logic the answer is 280ml

  14. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i.e. .5 = total ml acid / total ml solution (after you've added everything)

  15. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    good luck!

  16. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you

  17. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.