Question

1. The boiling point of ethanol, CH3CH2OH, is 78.500 °C at 1 atmosphere. Kb(ethanol) = 1.22...

1. The boiling point of ethanol, CH3CH2OH, is 78.500 °C at 1 atmosphere. Kb(ethanol) = 1.22 °C/m

In a laboratory experiment, students synthesized a new compound and found that when 11.40 grams of the compound were dissolved in278.0 grams of ethanol, the solution began to boil at 78.673 °C. The compound was also found to be nonvolatile and a non-electrolyte.


What is the molecular weight they determined for this compound ?

____ g/mol

2. Match the following aqueous solutions with the appropriate letter from the column on the right.

1. 0.16 m FeI2 A. Lowest freezing point
2. 0.15 m CoBr2 B. Second lowest freezing point
3. 0.22 m NH4NO3 C. Third lowest freezing point
4. 0.40 m Urea(nonelectrolyte) D. Highest freezing point
0 0
Add a comment Improve this question Transcribed image text
Answer #1

1)

Δ Tb = 78.673 - 78.500 = 0.17 oC

use:

Δ Tb = Kb*mb

0.173 = 1.22 *mb

mb= 0.1418 molal

m(solvent)= 278.0 g

= 0.278 kg

use:

number of mol,

n = Molality * mass of solvent in Kg

= (0.1418 mol/Kg)*(0.278 Kg)

= 3.942*10^-2 mol

mass(solute)= 11.40 g

use:

number of mol = mass / molar mass

3.942*10^-2 mol = (11.4 g)/molar mass

molar mass = 289.2 g/mol

Answer: 289.2 g/mol

Only 1 question at a time please

Add a comment
Know the answer?
Add Answer to:
1. The boiling point of ethanol, CH3CH2OH, is 78.500 °C at 1 atmosphere. Kb(ethanol) = 1.22...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • The boiling point of ethanol, CH3CH2OH, is 78.500 °C at 1 atmosphere. Kb(ethanol) = 1.22 °C/m...

    The boiling point of ethanol, CH3CH2OH, is 78.500 °C at 1 atmosphere. Kb(ethanol) = 1.22 °C/m In a laboratory experiment, students synthesized a new compound and found that when 13.27 grams of the compound were dissolved in 287.9 grams of ethanol, the solution began to boil at 78.706 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ? g/mol

  • The boiling point of ethanol, CH3CH,OH, is 78.500 °C at 1 atmosphere. Ky ethanol) = 1.22...

    The boiling point of ethanol, CH3CH,OH, is 78.500 °C at 1 atmosphere. Ky ethanol) = 1.22 °C/m In a laboratory experiment, students synthesized a new compound and found that when 12.13 grams of the compound were dissolved in 294.1 grams of ethanol, the solution began to boil at 78.685 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound? g/mol Submit Answer Retry Entire Group 9 more group...

  • The freezing point of ethanol, CH3CH2OH, is -117.300 °C at 1 atmosphere. Kf(ethanol) = 1.99 °C/m...

    The freezing point of ethanol, CH3CH2OH, is -117.300 °C at 1 atmosphere. Kf(ethanol) = 1.99 °C/m In a laboratory experiment, students synthesized a new compound and found that when 12.98 grams of the compound were dissolved in 255.2 grams of ethanol, the solution began to freeze at -117.651 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound? ------- g/mol

  • The freezing point of ethanol CH3CH2OH is -117.30°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves...

    The freezing point of ethanol CH3CH2OH is -117.30°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in ethanol is saccharin . How many grams of saccharin, C7H5NO3S (183.2 g/mol), must be dissolved in 268.0 grams of ethanol to reduce the freezing point by 0.300°C ? Kb=1.22 Kf=1.99

  • A. The boiling point of diethyl ether, CH3CH2OCH2CH3, is 34.500 °C at 1 atmosphere. Kb(diethyl ether)...

    A. The boiling point of diethyl ether, CH3CH2OCH2CH3, is 34.500 °C at 1 atmosphere. Kb(diethyl ether) = 2.02 °C/m In a laboratory experiment, students synthesized a new compound and found that when 10.22 grams of the compound were dissolved in 249.9 grams of diethyl ether, the solution began to boil at 34.714 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ? B. The boiling point of...

  • The boiling point ofchloroform, CHCl3, is61.700 °C at 1 atmosphere. Kb(chloroform) = 3.67 °C/m In a...

    The boiling point ofchloroform, CHCl3, is61.700 °C at 1 atmosphere. Kb(chloroform) = 3.67 °C/m In a laboratory experiment, students synthesized a new compound and found that when 12.35 grams of the compound were dissolved in 238.3 grams of chloroform, the solution began to boil at 62.398 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ? ____ g/mol

  • The boiling point of chloroform, CHCl3, is 61.700 °C at 1 atmosphere. Kb(chloroform) = 3.67 °C/m...

    The boiling point of chloroform, CHCl3, is 61.700 °C at 1 atmosphere. Kb(chloroform) = 3.67 °C/m In a laboratory experiment, students synthesized a new compound and found that when 12.07 grams of the compound were dissolved in 292.7 grams of chloroform, the solution began to boil at 62.540 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ? g/mol

  • The boiling point of water, H2O, is 100.000 °C at 1 atmosphere. Kb(water) = 0.512 °C/m...

    The boiling point of water, H2O, is 100.000 °C at 1 atmosphere. Kb(water) = 0.512 °C/m In a laboratory experiment, students synthesized a new compound and found that when 13.10 grams of the compound were dissolved in 212.3 grams of water, the solution began to boil at 100.092 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ? g/mol

  • The normal freezing point of ethanol (CH3CH2OH) is -117.300 °C and its Kfp value is 1.99...

    The normal freezing point of ethanol (CH3CH2OH) is -117.300 °C and its Kfp value is 1.99 °C/m. In a laboratory experiment, students synthesized a new compound and found that when 10.50 grams of the compound were dissolved in 214.0 grams of ethanol, the solution began to freeze at -117.639 °C. The compound was also found to be nonvolatile and a nonelectrolyte. What is the molecular weight they determined for this compound?

  • Match the following aqueous solutions with the appropriate letter from the column on the right. 1....

    Match the following aqueous solutions with the appropriate letter from the column on the right. 1. 0.16 m NiBr2 A. Lowest freezing point 2. 0.15 m Mg(NO3)2 B. Second lowest freezing point 3. 0.20 m MnSO4 C. Third lowest freezing point 4. 0.42 m Sucrose(nonelectrolyte) D. Highest freezing point 2.The boiling point of diethyl ether, CH3CH2OCH2CH3, is 34.500 °C at 1 atmosphere. Kb(diethyl ether) = 2.02 °C/m In a laboratory experiment, students synthesized a new compound and found that when...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT