1. Dismiss Notice
  2. Guest, be sure to check out How To Get Into Dental School, our free downloadable PDF with step-by-step details for dental school applicants!
    Dismiss Notice
  3. Dismiss Notice
  4. Download free Tapatalk for iPhone or Tapatalk for Android for your phone and follow the SDN forums with push notifications.
    Dismiss Notice

Gchem Ques

Discussion in 'DAT Discussions' started by Rock23, Aug 12, 2006.

  1. Rock23

    Rock23 Member
    2+ Year Member

    Joined:
    May 18, 2006
    Messages:
    41
    Likes Received:
    0
    Status:
    Pre-Dental
    Can anyone show me how to work this problem:

    How many grams of NaOH (40g/mol) are there in 250ml of 0.4 M NaOH solution? :oops:
     
  2. Note: SDN Members do not see this ad.

  3. allstardentist

    allstardentist All-Star
    10+ Year Member

    Joined:
    Apr 27, 2006
    Messages:
    927
    Likes Received:
    1
    Status:
    Dental Student
    .250L of soln x .4mol NaOH/1L solution x 40g of NaOH/1 mol = the answer.
     
  4. Harley comic

    Harley comic Junior Member
    2+ Year Member

    Joined:
    Jul 25, 2006
    Messages:
    25
    Likes Received:
    0
    Status:
    Pre-Dental
    Because M or Molarity = Mol of solute/kg of solvent. 1000ml = 1 kg
    Mol =(Molarity)*(kg of solvent)

    Just in case you wonder how to get the answer
     
  5. ernest1284

    ernest1284 Junior Member
    5+ Year Member

    Joined:
    Jul 8, 2006
    Messages:
    40
    Likes Received:
    0
    Status:
    Dental Student


    thats actually molality.... molality(m) = molessolute/kg solvent
    MOlarity is M so to do the problem (.250L)*(0.4M)=0.1000moles

    0.100moles*(40grams/1mol)=4.0grams
     
  6. Rock23

    Rock23 Member
    2+ Year Member

    Joined:
    May 18, 2006
    Messages:
    41
    Likes Received:
    0
    Status:
    Pre-Dental
    thanks allstar for the help!
     
  7. allstardentist

    allstardentist All-Star
    10+ Year Member

    Joined:
    Apr 27, 2006
    Messages:
    927
    Likes Received:
    1
    Status:
    Dental Student
  8. Harley comic

    Harley comic Junior Member
    2+ Year Member

    Joined:
    Jul 25, 2006
    Messages:
    25
    Likes Received:
    0
    Status:
    Pre-Dental
    Thanks for the clarity. I alway messed up
    these two guys,
    Molarity and molality
     

Share This Page