Chemistry

posted by .

What is the molality of a glucose solution prepared by dissolving 18.0g of glucose, C6H12O6 in 125g of water?
A)0.000794
B)0.144
C)0.699
D)0.794

Molality is the number of moles of solute per kilogram of solvent. Because the density of water at 25°C is about 1 kilogram per liter, molality is approximately equal to molarity for dilute aqueous solutions at this temperature. This is a useful approximation, but remember that it is only an approximation and doesn't apply when the solution is at a different temperature, isn't dilute, or uses a solvent other than water.

Example:
What is the molality of a solution of 10 g NaOH in 500 g water?

Solution:
10 g NaOH / (4 g NaOH / 1 mol NaOH) = 0.25 mol NaOH
500 g water x 1 kg / 1000 g = 0.50 kg water
molality = 0.25 mol / 0.50 kg
molality = 0.05 M / kg
molality = 0.50 m

hope this helps.....let me know if you need more help


The example looks good but there is a typo. 4g NaOH should read 40 g NaOH/mol.

  • Chemistry -

    WHAT IS 1MOLAL SOLUTION

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chemistry

    A solution of HCI has a density of 1.18 g/ml and is 36% (m/m). what is the molarity and molality of this solution?
  2. CHEMISTRY MOLALITY!!!!!

    A bottle of wine contains 13.1% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality. i don't know how to get molality. please help!!!! …
  3. chemistry

    A commercial sample of concentrated aqueous nitric acid (HNO3) is 18.2% nitric acid base mass and has a density of 1.12 g/mL. (a) What is the molarity (M) of the HNO3 solution?
  4. AP Chemistry

    A 25.0g sample of glucose, C6H12O6, dissolves in 525mL of distilled water. a. what is the boiling point elevation of the solution over the pure solvent?
  5. chemistry

    A solution is prepared by dissolving 49.0 g of glucose (C6H12O6) in 225.0 g of water. The density of the resulting solution is 1.23 g/mL. Determine the osmotic pressure (in Pa) of this solution at 25.0 oC.
  6. Chemistry

    A 5.00-gram sample of glucose, C6H12O6, [molar mass = 180.] is dissolved 10.0 grams of water What is the molality of the glucose solution?
  7. chemistry

    A glucose solution contains 55.8g of glucose (C6H12O6) in 455g of water. Calculate the freezing poing and boiling point of the solution. (Assume a density of 1.00 g/ml for water. This what I did, I got moles of C6H12O6, 0.89 moles …
  8. Chemistry

    An aqueous solution is 8.50% ammonium chloride, NH4Cl, by mass. The density of the solution is 1.024g/mL. Calculate the molality, mole fraction, and molarity of NH4Cl in the solution. I know the formulas needed but I'm not sure where …
  9. chemistry

    A solution was made by dissolving 62.07 grams of a compound in 500.0 g of water. The compound was not ionic. The freezing point of the solution was measured and found to be – 1.86oC. Using the Kf value in your textbook , the molar …
  10. CHEMISTRY

    Dye of iodine is prepared by dissolving in ethanol , and 1% ( one percent ) of this solution contains 10 g of solute in 1000 g of solution 1) how many grams of solvent is there in the solution ?

More Similar Questions