# chemistry

posted by .

After you preform your experiment, you determine that the Kf value for naphthalene is 6.9 . You are using 10g of naphthalene and added 1.0 g of your unknown. The the freezing point of the solvent decreased by 4.42 when the unknown was added. Knowing this information, determine the molar mass of the unknown

• chemistry -

delta T = Kf*m
Solve for m

m = moles/kg solvent
Solve for moles

moles = grams/molar mass
Solve for molar mass.

## Similar Questions

1. ### Naphthalene

Question: You are about to purify an impure sample of naphthalene by column chromatography. What solvent should you use to elute the sample?
2. ### Chemisty-Freezing Points

The freezing point of benzene is 5.5°C. What is the freezing point of a solution of 8.50 g of naphthalene (C10H8) in 425 g of benzene (Kf of benzene = 4.90°C/m)?
3. ### 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. …
4. ### chemistry

If Pdcb replaces naphthalene as an active ingredient in mothballs , what is the value of kf for camphor if a 0.260 m solution of PDCB in camphor decreases the freezing point of camphor by 9.8 degrees C. I am sure that you will use …
5. ### CHEM- solution/freezing piont

a solution of sulfur (2.560g) in naphthalene (100g) freezes 0.68K lower the freezing point of pure naphthalene (353.10K). for naphthalene, Kf= 6.8K kg mol. calculatem the molecular formula of the sulfur dissolved in the naphthalene?
6. ### chemistry

Naphthalene, commonly known as moth balls, is composed of 93.7% carbon and 6.3% hydrogen. determine the empirical for naphthalene. molecular formula for Naphthalene. Determine the number of empirical formulas you would need to make …
7. ### chemistry

When 4.167 g of a unknown compound is added to 34.1 g of a particular solvent, the freezing point of that solvent decreases by 0.8 °C. Determine the molar mass of the unknown compound. (The freezing point constant of the solvent is …
8. ### Chemistry

The equation for lowering the freezing point of a solvent is given in your manual. Given that the freezing point for the pure solvent is 79.4 °C , the molality is 0.1 m , and the freezing point depression constant is 6.9 °C/m , determine …
9. ### Chemistry

After you preform your experiment, you determine that the Kf value for naphthalene is 6.89 °C/m . You are using 10g of naphthalene and added 1.0 g of your unknown. The the freezing point of the solvent decreased by 4.42 °C when the …
10. ### Chemistry

Benzene (C6H6) has a normal freezing point of 5.50oC and a density of 0.88 g/mL. When 1.28 g of naphthalene (C10H8) is dissolved in 125 mL of benzene, the freezing point of the solution is 5.03oC. Determine the molal freezing point …

More Similar Questions