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
katrin [286]
3 years ago
13

The standard free energy of formation, ΔG∘f, of a substance is the free energy change for the formation of one mole of the subst

ance from the component elements in their standard states. These values are applicable at 25 ∘C and are found in thermodynamic tables.
The value of ΔG∘f for a substance gives a measure of the thermodynamic stability with respect to the component elements. Negative values for a formation reaction indicate thermodynamic stability of the product. In other words, the compound formed does not spontaneously decompose back into the component elements. Positive values for a formation reaction indicate thermodynamic instability of the product. Thus, the compound will spontaneously decompose, though the rate may be slow.

The sign of ΔG∘f can be used to predict the feasibility of synthesizing a substance from its component elements. The standard free energy change for a reaction, ΔG∘, is a state function and can be calculated from the standard free energies of formation as follows:

ΔG∘rxn=∑npΔG∘f(products)−∑nrΔG∘f(reactants)

where np and nr represent the stoichiometric coefficients in the balanced chemical equation for the reactants and products respectively.

Based on the standard free energies of formation, which of the following reactions represent a feasible way to synthesize the product?

A. N2(g)+H2(g)→N2H4(g); ΔG∘f=159.3 kJ/mol
B. 2Na(s)+O2(g)→Na2O2(s); ΔG∘f=−451.0 kJ/mol
C. 2C(s)+2H2(g)→C2H4(g); ΔG∘f=68.20 kJ/mol
D. 2SO(g)+O2(g)→2SO2(g); ΔG∘f=−600.4 kJ/mol
Chemistry
1 answer:
OLEGan [10]3 years ago
3 0

Answer:

B. 2 Na(s) + O₂(g) → Na₂O₂(s); ΔG∘f=−451.0 kJ/mol

D. 2 SO(g) + O₂(g) → 2 SO₂(g); ΔG°f=−600.4 kJ/mol

Explanation:

The spontaneity of a reaction  is given by the value of the standard Gibbs free energy of the reaction (ΔG°rxn). The more negative is the ΔG°rxn, the more spontaneous is a reaction.

The ΔG°rxn can be calculated using the following expression:

ΔG°rxn = ∑np × ΔG°f(products) − ∑nr × ΔG°f(reactants)

By definition, the standard Gibbs free energy of formation of simple substances in their most stable state is zero. That is why, in the reaction of formation of a compound ΔG°rxn = ΔG°f(product).

<em>Based on the standard free energies of formation, which of the following reactions represent a feasible way to synthesize the product? </em>

<em>     A. N₂(g) + H₂(g) → N₂H₄(g); ΔG°f=159.3 kJ/mol. </em>

<em>     </em>Not feasible. ΔG°rxn = ΔG°f(product) > 0.

    <em>B. 2 Na(s) + O₂(g) → Na₂O₂(s); ΔG°f=−451.0 kJ/mol</em>

    Feasible. ΔG°rxn = ΔG°f(product) < 0.

    <em>C. 2 C(s) + 2 H₂(g) → C₂H₄(g); ΔG°f=68.20 kJ/mol</em>

    Not feasible. ΔG°rxn = ΔG°f(product) > 0.

    <em>D. 2 SO(g) + O₂(g) → 2 SO₂(g); ΔG°f=−600.4 kJ/mol</em>

    Feasible. ΔG°rxn = ΔG°f(product) < 0.

You might be interested in
Which of the following is an example of a chemical change?
Vsevolod [243]

Answer:

D

Explanation:

It is D because once youve put together the ingredients and baked it you can not go in and taake out every ingredient and put it back to how it was before (Please also try to help me with my question it it about scaled copies, Please and thank you!)

6 0
2 years ago
Read 2 more answers
If you have a solution that is 15 percent by mass of KCl in benzene, what is the new boiling point?
Serhud [2]

Answer:

https://www.chegg.com/homework-help/questions-and-answers/1-10-points-solution-15-percent-mass-kcl-benzene-new-boiling-point--901-c-b-921-c-c-821-c--q63751186

Explanation: Thats your answer

3 0
2 years ago
A small, hard-shelled fossil that resembles a modern-day ocean organism was found
Paul [167]

Answer:

The desert was one covered by ocean water.

Explanation:

5 0
2 years ago
What is the volume of a gas if 0.182 moles of the gas is at 1.99 atm and 83.4oC?
Sunny_sXe [5.5K]

Answer:

2,67 L

Explanation:

8 0
2 years ago
Name an element in the third period (row) of the periodic table with a total of 4 3p electrons
Wittaler [7]

Answer:

sulfur

Explanation:

sulfur has 4p electrons.

phosphorus has 3p electrons.

The question is asking which one has 4

3 0
2 years ago
Other questions:
  • 10. (2 points) What is the process by which a solute forms a solution in a solvent. A) calisthenics B) bumping C) dissolution D)
    14·1 answer
  • The coefficients in a chemical equation represent the
    11·1 answer
  • Which boiling point is lower an why?
    8·2 answers
  • 14 someone help ASAP
    13·1 answer
  • Disorder of the particles of a liquid decreases the freezing point. True or false
    6·1 answer
  • The following reaction was carried out in a 2.00 L reaction vessel at 1100 K: C(s)+H2O(g)⇌CO(g)+H2(g) If during the course of th
    14·1 answer
  • Assessment
    15·1 answer
  • How is a warm front formation diffrent from occlued front formation​
    6·1 answer
  • Please help !!! (no links or ill report)
    13·1 answer
  • Fill in the blank ......
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!