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
daser333 [38]
2 years ago
5

4. a compound called pyrene has the empirical formula c8h5. when 4.04 g of pyrene is dissolved in 10.00 g of benzene, the boilin

g point of the solution is 85.1°c calculate the molar mass of pyrene and determine its molecular formula. the molal boiling-point constant for benzene is 2.53°c/m. its normal boiling point is 80.1°c
Chemistry
1 answer:
e-lub [12.9K]2 years ago
3 0

The molecular mass of pyrene is 204.4 g/mol.

From;

ΔT = Kb m i

Where;

  • ΔT = boiling point elevation
  • Kb = boiling point constant
  • m = molality
  • i = Van't Hoff factor

Since the compound is molecular; i = 1

The number of moles of pyrene = 4.04 g/MM

Where; MM = molar mass of pyrene

molality = number of moles of pyrene/mass of solvent in Kg

The mass of solvent = 10 g or 0.01 Kg

molality =  4.04 g/MM/0.01

ΔT = Boiling point of solution - Boiling point of pure solvent

ΔT = 85.1°C - 80.1°C

ΔT = 5°C

5 = 2.53 × 4.04 g/MM/0.01 × 1

5 = 10.22 × 1/0.01 MM

0.05MM = 10.22

MM= 10.22/0.05

MM= 204.4 g/mol

Learn more: brainly.com/question/2292439

You might be interested in
CH4(g)+O2(g)→CO2(g)+H2O(g). What mass of water is produced from the complete combustion of 5.00×10−3 g of methane?
bixtya [17]

Answer:

1gram of water

Explanation:

First balance the equation

Ch4+2O2>CO2+2H2O

Ratio is 1:2

500×10-3what about 2?

500×10-3×2=1g

1g of water

4 0
3 years ago
Ammonia (NH3) clouds are present around some planets. Calculate the number of grams of ammonia produced by the reaction of 5.4 g
Komok [63]

Answer:

30.4 g. NH3

Explanation:

This problem tells us that the hydrogen (H2) is the limiting reactant, as there is "an excess of nitrogen." Using stoichiometry (the relationship between the various species of the equation), we can see that for every 3 moles of H2 consumed, 2 moles of NH3 are produced.

But before we can use that relationship to find the number of grams of ammonia produced, we need to convert the given grams of hydrogen into moles:

5.4 g x [1 mol H2/(1.008x2 g.)] = 2.67857 mol H2 (not using significant figures yet; want to be as accurate as possible)

Now, we can use the relationship between H2 and NH3.

2.67857 mol H2 x (2 mol NH3/3 mol H2) = 1.7857 mol NH3

Now, we have the number of moles of ammonia produced, but the answer asks us for grams. Use the molar mass of ammonia to convert.

1.7857 mol NH3 x 17.034 g. NH3/mol NH3 = 30.4 g. NH3 (used a default # of 3 sig figs)

5 0
3 years ago
Read 2 more answers
Please Help!!!
STatiana [176]

Answer:

single replacement

Explanation:

Step 1: Data given

single replacement = A reaction in which one element replaces a similar element in a compound. For example, a metal replaces an other metal.

The general form of a single-replacement (also called single-displacement) reaction is:

A+BC→AC+B

Decomposition = a reaction in which a compound breaks down into two or more simpler substances. The general form of a decomposition reaction is:

AB→A+B

Synthesis =  A reaction that occurs when one or more compounds combines to form a complex compound:

A + B → AB

Double replacement: a reaction in which the positive and negative ions of two ionic compounds exchange places to form two new compounds.

The general form of a double-replacement reaction is:

AB+CD→AD+BC

Combustion reaction = a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat. Combustion reactions must involve  O2  as one reactant.

The reaction Zn + 2HCl → ZnCl2 + H2

⇒ Does not involve O2 = NOT a combustion reaction

⇒ The compounds do not form a complex compound = NOT a synthesis

⇒ A compound does not break down into smaller substances = NOT a decomposition

⇒ There is a replacement between Zn and H. This is a <u>single replacement</u>, not a double replacement reaction.

6 0
3 years ago
Assuming that both cases describe hydrogen‑like atoms with one electron, for which case is more energy emitted or absorbed?
Nana76 [90]

Assuming that both cases describe hydrogen‑like atoms with one electron, More energy is emitted or absorbed for case 2. The correct option is D.

<h3>What is emitting of energy, by electron?</h3>

The energy of the electron decreases as it changes levels, and emission of photons happens in the atom.

With the electron moving from a higher to a lower energy level, the photon is emitted. The photon's energy is the same as the energy lost by an electron moving to a lower energy level.

Thus, the correct option is D, More energy is emitted or absorbed for case 2.

Learn more about emitting of energy

brainly.com/question/14350185

#SPJ4

5 0
2 years ago
In an aqueous solution of potassium chloride the solute is
Goryan [66]

Answer:

Potassium chloride

Explanation:

A solution is formed by a solvent and one or more solutes.

The solvent is the species that is in major proportion and usually defines the state of aggregation of the solution, while the solute/s is/are in minor proportion.

Also, water is known as the universal solvent, so in any solution containing water, it is considered as the solvent.

Then, in an aqueous solution of potassium chloride the solute is potassium chloride.

7 0
3 years ago
Other questions:
  • The water in a 2500-L aquarium contains 1.25 g of copper. Calculate the concentration of copper in the water in ppm (remember 1
    14·1 answer
  • If you take energy away from oxygen, will it turn into water? If not, then what will turn into water if you take away energy fro
    6·1 answer
  • A closed circle with short lines inside on a topographical map
    14·2 answers
  • According to the kinetic theory _____.
    12·2 answers
  • If boiling water were poured into a China cup and a foam cup which cup would feel hotter?explain.
    8·2 answers
  • Predict what you need to do do to use boyle’s law on a macroscopic scale
    11·1 answer
  • La siguiente formula K2Cr2O7 corresponde al
    14·1 answer
  • HELP ASAP
    8·2 answers
  • select the correct answer from each drop down menu how do you the freezing point and boiling point of a solution compare with th
    5·1 answer
  • A student measured out 0.333 moles of theobromine, CyH3N402 (MM = 180.8/mol) the
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!