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Gchem Ques

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

  1. Rock23

    Rock23 Member
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    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:
     
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  3. allstardentist

    allstardentist All-Star
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    .250L of soln x .4mol NaOH/1L solution x 40g of NaOH/1 mol = the answer.
     
  4. Harley comic

    Harley comic Junior Member
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    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
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    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
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    thanks allstar for the help!
     
  7. allstardentist

    allstardentist All-Star
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  8. Harley comic

    Harley comic Junior Member
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    Thanks for the clarity. I alway messed up
    these two guys,
    Molarity and molality
     

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