1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
mel-nik [20]
3 years ago
5

For the solution resulting from dissolved 0.32 g of naphthalene (C10H8) in 25 g of benzene (C6H6) at temperature of 26.1°C, calc

ulate the vapor pressure lowering, the boiling point elevation, and the freezing point depression. The vapor pressure of benzene at the temperature of the experiment is 100 torr. (Kf of benzene = 2.67 °C/m, Kb of benzene = 5.12 °C/m)
Chemistry
1 answer:
grandymaker [24]3 years ago
5 0

Answer:

See explanation

Explanation:

Number of moles of naphthalene = 0.32g/128.1705 g/mol = 0.0025 moles

Molality = number of moles/ mass of Solvent in kilograms

Molality = 0.0025/0.025 Kg

Morality = 0.1 m

But

∆T= K × i × m

Where ∆T = boiling point elevation

i= number of particles (this is equal to 1 because naphthalene is molecular and not ionic)

m= molality of naphthalene = 0.1 m

K= boiling point elevation constant = 5.12 °C/m

∆T= 5.12 °C/m ×0.1 = 0.512°C

For freezing point depression

∆T= K× i × m

Where ∆T= freezing point depression

i= number of particles (this is equal to 1 because naphthalene is molecular and not ionic)

m= molality of naphthalene = 0.1 m

K= freezing point depression constant = 2.67 °C/m

∆T= 2.67 °C/m ×0.1 = 0.267°C

From Raoult's law;

∆P = XBPA°

Where;

∆P = vapour pressure lowering

XB = mole fraction of solute

PA° = vapour pressure of pure solvent

Number of moles of solvent = mass/molar mass = 25g/ 78 g/mol= 0.3205 moles

Total number of moles = number of moles of solute + number of moles of solvent = 0.0025 moles + 0.3205 moles = 0.323 moles

Mole fraction of solute = 0.0025 moles/0.323 moles = 0.0077

Vapour pressure of benzene = 100 torr

Therefore;

∆P = 0.0077 × 100torr = 0.77 torr

Hence;

∆P = 0.77 torr

You might be interested in
Nitrogen (N) has an atomic number of 7 and an atomic mass of 14. Which of the following correctly shows the electron arrangement
bonufazy [111]

Answer:

2, 5

Explanation:

3 0
3 years ago
Read 2 more answers
2 Which is NOT a function of the skeletal system? A. It gives support to your body. B. It protects your internal organs. C. Bone
timofeeve [1]

Answer:

C. Bones carry impulses to the nervous system.

Explanation:

hop this helps

8 0
2 years ago
It takes 495.0 kJ of energy to remove 1 mole of electron from an atom on the surface of sodium metal. How much energy does it ta
Zigmanuir [339]

Answer:

\lambda=241.9\ nm

Explanation:

The work function of the sodium= 495.0 kJ/mol

It means that  

1 mole of electrons can be removed by applying of 495.0 kJ of energy.

Also,  

1 mole = 6.023\times 10^{23}\ electrons

So,  

6.023\times 10^{23} electrons can be removed by applying of 495.0 kJ of energy.

1 electron can be removed by applying of \frac {495.0}{6.023\times 10^{23}}\ kJ of energy.

Energy required = 82.18\times 10^{-23}\ kJ

Also,  

1 kJ = 1000 J

So,  

Energy required = 82.18\times 10^{-20}\ J

Also, E=\frac {h\times c}{\lambda}

Where,  

h is Plank's constant having value 6.626\times 10^{-34}\ Js

c is the speed of light having value 3\times 10^8\ m/s

So,  

79.78\times 10^{-20}=\frac {6.626\times 10^{-34}\times 3\times 10^8}{\lambda}

\lambda=\frac{6.626\times 10^{-34}\times 3\times 10^8}{82.18\times 10^{-20}}

\lambda=\frac{10^{-26}\times \:19.878}{10^{-20}\times \:82.18}

\lambda=\frac{19.878}{10^6\times \:82.18}

\lambda=2.4188\times 10^{-7}\ m

Also,  

1 m = 10⁻⁹ nm

So,  

\lambda=241.9\ nm

6 0
3 years ago
Explain why beryllium is produced when potassium is heated with beryllium
Vladimir [108]

Explanation:

The more reactive element replaces less reactive element during chemical reaction.

Since, potassium is more reactive than beryllium. When potassium reacts with beryllium choride, it replaces beryllium and forms potassium chloride and produces beryllium.

3 0
2 years ago
Which statement about chemical reaction rates is true?
aniked [119]

Answer:

C

Explanation:

gggggggggggggggggggggggggggggggg

gg

3 0
3 years ago
Read 2 more answers
Other questions:
  • Some molecules that are covalently bonded do not have a difference in charge across the molecule. These molecules are referred t
    15·1 answer
  • !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    14·1 answer
  • A solution contains [Ba2+] = 5.0 × 10−5 M, [Zn2+] = 2.0 × 10−7 M, and [Ag+] = 3.0 × 10−5 M. Sodium oxalate (Na2C2O4) is slowly a
    7·1 answer
  • Describe how the phases of the moon depend on the positions of the earth and the moon brainly
    9·2 answers
  • Adenosine triphosphate (ATP) is the main energy currency used in cells. ATP hydrolysis is coupled with unfavorable reactions, ma
    6·1 answer
  • Only the _______
    14·1 answer
  • Why don't we use the plutonium (Pu) from reprocessed/used nuclear fuel? There are 2 correct answers. (this is for my earth scien
    5·1 answer
  • Please help me with 1,2,3,4,5,6 please I really need help
    12·1 answer
  • Write the number below in scientific notation rounded off to 3 significant figures.
    10·1 answer
  • Flat vs. Fizzy Soda (If you have the answers for the rest of the questions 9-17 please let me know) thankyou!
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!