Chemistry

Calculate the molar mass of a compound that raises the boiling point of water to 100.15oC when 40.5 g of the compound is dissovled in 500 g of water.

and

A mass of 41 g of an unknown nonelectrolyte is dissolved in 429 g naphthalene. The nonelectrolyte lowers naphthalene's freezing point by 7.2 oC. What is the molecular mass of the unknown substance? (Kf = 6.8 oC/mola

  1. 👍 0
  2. 👎 0
  3. 👁 202
  1. #1.
    a. delta T = Kb*molality
    You know delta T and Kb, solve for molality.
    b. Then molality = mols/kg solvent.
    You know molality and kg solvent, solve for mols.
    c. mols = grams/molar mass. You know mols and grams, solve for molar mass.

    #2.
    Same kind as #1. Post your work if you get stuck.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    Some physical properties of water are shown below. freezing point 0.00°C boiling point 100.00°C Kf 1.86°C/m Kb 0.512°C/m A 16.0 g sample of a compound known to contain 3 ion species is dissolved in 100. g of water. The boiling

    asked by Tiffany on September 9, 2010
  2. Chemistry

    A 16.0 g sample of a compound known to contain 3 ion species is dissolved in 100. g of water. The boiling point of the solution is 103.1°C. What is the molar mass of the compound?

    asked by Jade on September 11, 2013
  3. Ochem

    What volume of eugenol will be present in 30 mL of distillate? The essential oil found in cloves, eugenol, can be isolated by steam distillation because it is insoluble in water and has a measurable vapor pressure at 100 °C even

    asked by Chem on August 4, 2014
  4. chemistry

    Based on molecular mass and boiling point of the five compounds in the table below, which should have the high? est dipole moment: first # molecular mass 2nd: boiling point compound 1 244 203 compound 2 346 255 compound 3 250 138

    asked by ben on December 13, 2010
  5. 11th grade

    Calculate the molecular mass of the nonionic solutes: 64.3 g of solute in 390 g of water raises the boiling point to 100.680 degrees C.

    asked by Chum on August 4, 2010
  1. chemistry

    A 2.97 g sample of a molecular compound is dissolved in 103 g of tetrachloromethane (carbon tetrachloride). The normal boiling point of the solution is 61.51C, the normal boiling point of CCl4 is 61.2C. The boiling point

    asked by Aubrey on December 6, 2011
  2. Chemistry

    A solution was prepared by dissolving 72.0 g of glucose in 300.0 g of water. The ressulting solution was found to have a boiling point of 100.68C at 1 atm. Calculate the molar mass of glucose. For water Kb= 0.51 Ckg/mol. I know

    asked by Naomi on June 8, 2018
  3. Chemistry

    The mass of a sample of a liquid compound was found to be 0.534 g after the compound was vaporized in a containter placed in a boiling water bath at 100°C at 748 torr. The volume of the container was 286mL. Calculate the

    asked by Anonymous on October 24, 2011
  4. AP Chem

    A 1.73 g sample of a molecular compound is dissolved in 105 g of tetrachloromethane (carbon tetrachloride). The normal boiling point of the solution is 61.51C, the normal boiling point of CCl4 is 61.2C. The boiling point

    asked by John Smith on December 12, 2012
  5. chemistry

    an aqueous solution containing 17.5g of an unknown molecular(nonelectrolyte) compound in 100.0g of water has a freezing point of 1.8 degress C. calculate the molar mass of the unknown compound

    asked by Monique on November 5, 2011

More Similar Questions