Results 1 to 3 of 3

Math Help - Find Molarity

  1. #1
    Member
    Joined
    Jan 2009
    From
    Ontario Canada
    Posts
    219

    Find Molarity

    50ml of stock H2SO4(density = 1.52g/ml,62%w/w) in 500 ml solution.

    I am doing practice test questions and this is the only one I can not figure out. Any way I have tried it I still can't come up with the answer of .96M.

    Can someone help me with the steps?
    Thanks
    do I calculate the gram in solute first?

    Any help would be great, thanks.

    What is meant by stock??
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member rtblue's Avatar
    Joined
    Mar 2009
    From
    Birmingham, Alabama.
    Posts
    221
    Remember molarity is defined by (moles/liters). We know the liters: 0.5 liters.

    1. Convert 50ml into grams (we have the density)

    2. Note that the problem says 62%w/w. This means 62% by weight. So only 62% of the grams you get here is H_2SO_4 and to account for this, we must multiply the mass we get by 0.62, and that is actually how many grams of sulfuric acid we have.

    3. Convert grams to moles

    4. Divide that number of moles by the liters (0.5) and you have your molarity.

    P.S. The word stock is irrelevant.

    Once these calculations have been done, I do get 0.96M
    Last edited by rtblue; December 5th 2010 at 05:21 PM.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jan 2009
    From
    Ontario Canada
    Posts
    219
    Thank you, I got it from your direction. that helps me with the other 2 problems now.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calculating Molarity Help
    Posted in the Math Topics Forum
    Replies: 4
    Last Post: March 6th 2011, 03:41 PM
  2. Replies: 2
    Last Post: March 1st 2011, 03:09 PM
  3. Chemistry- Acid base titration find molarity
    Posted in the Math Topics Forum
    Replies: 0
    Last Post: February 8th 2010, 10:17 AM
  4. Help me find Molarity
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: January 30th 2009, 06:23 PM
  5. Help with finding Molarity?
    Posted in the Math Topics Forum
    Replies: 0
    Last Post: January 30th 2009, 04:12 AM

Search Tags


/mathhelpforum @mathhelpforum