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
alina1380 [7]
2 years ago
10

When 551. mg of a certain molecular compound X are dissolved in 100 g of benzonitrile (CH,CN), the freezing point of the solutio

n is measured to be 13.4 °C. Calculate the molar mass of X.
Chemistry
1 answer:
arsen [322]2 years ago
5 0

Answer:

1.12g/mol

Explanation:

The freezing point depression of a solvent for the addition of a solute follows the equation:

ΔT = Kf*m*i

<em>Where ΔT is change in temperature (Benzonitrile freezing point: -12.82°C; Freezing point solution: 13.4°C)</em>

<em>ΔT = 13.4°C - (-12.82) = 26.22°C</em>

<em>m is molality of the solution</em>

<em>Kf is freezing point depression constant of benzonitrile (5.35°Ckgmol⁻¹)</em>

<em>And i is Van't Hoff factor (1 for all solutes in benzonitrile)</em>

Replacing:

26.22°C = 5.35°Ckgmol⁻¹*m*1

4.90mol/kg = molality of the compound X

As the mass of the solvent is 100g = 0.100kg:

4.9mol/kg * 0.100kg = 0.490moles

There are 0.490 moles of X in 551mg = 0.551g, the molar mass (Ratio of grams and moles) is:

0.551g / 0.490mol

= 1.12g/mol

<em>This result has no sense but is the result by using the freezing point of the solution = 13.4°C. Has more sense a value of -13.4°C.</em>

You might be interested in
A sample of 1.00 moles of oxygen at 50°C and 98.6 kPa, occupies what volume?
enyata [817]

Answer:

27.22 dm³

Explanation:

Given parameters:

number of moles = 1 mole

temperature= 50°C, in K gives 50+ 273 = 323K

Pressure= 98.6kpa in ATM, gives 0.973 ATM

Solution:

Since the unknown is the volume of gas, applying the ideal gas law will be appropriate in solving this problem.

The ideal gas law is mathematically expressed as,

Pv=nRT

where P is the pressure of the gas

V is the volume

n is the number of moles

R is the gas constant

T is the temperature

Input the parameters and solve for V,

0.973 x V = 1 x 0.082 x 323

V= 27.22 dm³

5 0
3 years ago
When the temperature of a rigid hollow sphere containing 685 L of helium gas is held at 621 K, the pressure of the gas is 1.89 x
Leno4ka [110]
You have to use the equation PV=nRT.
P=pressure (in this case 1.89x10^3 kPa which equals 18.35677 atm)
1V=volume (in this case 685L)
n=moles (in this case the unknown)
R=gas constant (0.08206 (L atm)/(mol K))
T=temperature (in this case 621 K)
with the given information you can rewrite the ideal gas law equation as n=PV/RT.
n=(18.35677atm x 685L)/(0.08206atmL/molK x 621K)
n=246.8 moles
8 0
2 years ago
How many grams in a kilogram,how many quarts are in a pint and if how many ml of h20 = 1g
vodomira [7]

Answer:

1 g  +  10 g

Explanation:

5 0
3 years ago
Read 2 more answers
Why are some amino acids described as essential amino acids?
SCORPION-xisa [38]

Answer:

I would say A and D if you can pick two answers. if not then pick D

6 0
3 years ago
Read 2 more answers
How many elements are in “C2H6O”
Maru [420]

Answer:

Ethanol's chemical formula is C2H6O. This chemical formula can also be written as CH3CH2OH or C2H5OH. It is made of nine atoms that include two carbon (C) atoms, six hydrogen (H) atoms, and one oxygen (O) atom.

Explanation:

8 0
2 years ago
Read 2 more answers
Other questions:
  • 8. How long does it take a 19 kW steam engine to do 6.8 x 107 J of work?
    5·1 answer
  • What is the ∆G for the following reaction under standard conditions (T = 298 K) for the formation of NH4NO3(s)? 2NH3(g) + 2O2(g)
    11·2 answers
  • what mass of lithium chloride, licl must be dissolved to make a 0.194M solution that has volume of 1.00 l
    6·1 answer
  • Can you answer the following questions with work, please?A) The conversion of glucose-6-phosphate to fructose-6-phosphate is cat
    12·1 answer
  • Which state of matter is most likely represented in the diagram shown below?
    9·2 answers
  • The nucleus of one boron atom has 5 protons and 4 neutrons. Determine the total charge of the boron.
    7·2 answers
  • The combination of the atoms of two or more elements is known as a/an
    12·2 answers
  • Which process transfers heat when particles collide in a solid
    6·1 answer
  • How many moles are there in 1.505 X 1024 molecules of water, H2O?
    11·1 answer
  • Questions
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!