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
love history [14]
3 years ago
9

A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that

of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol
Chemistry
1 answer:
UkoKoshka [18]3 years ago
6 0

Answer:

The correct answer is 146 g/mol

Explanation:

<em>Freezing point depression</em> is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:

ΔTf = Kf x m

Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:

ΔTf = 1.02ºC

Kf = 5.12ºC/m

From this, we can calculate the molality:

m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m

The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:

0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute

There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:

molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol

<em>Therefore, the molar mass of the compound is 146 g/mol </em>

You might be interested in
Which of the following is the unit of surface tension?​
nekit [7.7K]

Answer:

it should be N/m or newton per meter.

6 0
3 years ago
Draw the Lewis structure of PH3. To add lone pairs, click the A lone pair button has two dots. button before clicking on the mol
sattari [20]

Answer:

a

Explanation:

4 0
3 years ago
Draw the structures of the following covalent molecules.
zysi [14]

NHCl_2=Attachment 1

SiO_2=Attachment 2

SO_2=Attachment 3

BF_3=Attachment 4

CF_2H_2=Attachment 5

8 0
2 years ago
Read 2 more answers
At the normal melting point of NaCl, 801 degrees C, its enthalpy of fusion is 28.8 kJ / mol. The density of the solid is 2.165 g
melisa1 [442]

<u>Answer:</u> The increase in pressure is 0.003 atm

<u>Explanation:</u>

To calculate the final pressure, we use the Clausius-Clayperon equation, which is:

\ln(\frac{P_2}{P_1})=\frac{\Delta H}{R}[\frac{1}{T_1}-\frac{1}{T_2}]

where,

P_1 = initial pressure which is the pressure at normal boiling point = 1 atm

P_2 = final pressure = ?

\Delta H = Enthalpy change of the reaction = 28.8 kJ/mol = 28800 J/mol     (Conversion factor: 1 kJ = 1000 J)

R = Gas constant = 8.314 J/mol K

T_1 = initial temperature = 801^oC=[801+273]K=1074K

T_2 = final temperature = (801+1.00)^oC=802.00=[802+273]K=1075K

Putting values in above equation, we get:

\ln(\frac{P_2}{1})=\frac{28800J/mol}{8.314J/mol.K}[\frac{1}{1074}-\frac{1}{1075}]\\\\\ln P_2=3\times 10^{-3}atm\\\\P_2=e^{3\times 10^{-3}}=1.003atm

Change in pressure = P_2-P_1=1.003-1.00=0.003atm

Hence, the increase in pressure is 0.003 atm

6 0
3 years ago
In what way is psychology connected to the natural sciences and different than other social sciences?
Maksim231197 [3]
Answer: A
It explored the influences of society on individuals and their behavior
4 0
2 years ago
Other questions:
  • Correct each of the following statements: (a) In the modern periodic table, the elements are arranged in order of increasing ato
    5·1 answer
  • 3. compared to the melting points of ionic compounds, the melting points of molecular solids tend to be ___.
    5·2 answers
  • Calculate ΔH∘f (in kilojoules per mole) for benzene, C6H6, from the following data: 2C6H6(l) + 15O2(g)→12CO2(g)+6H2O(l) ΔH∘=−653
    10·1 answer
  • Difference between Atom and Molecule <br> In three points
    11·2 answers
  • To make a 2 M solution of calcium chloride (CaCl2), you would place how many grams of CaCl2 into a container and then add how mu
    9·1 answer
  • How many moles are in 45.8 g of calcium nitrate, Ca(NO3)2? PLEASE HELP
    12·1 answer
  • What volume of 5 M NaOH is needed to create a 100 mL solution of 1 M NaOH?
    7·1 answer
  • How does the Law of Conservation of Matter apply to you when you eat food? Why do you not continuously gain exactly the amount o
    5·1 answer
  • Is copper and silver nitrate a physical change or Chemical change
    9·1 answer
  • What volume will 5.6 moles of sulfur hexafluoride
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!