Which of the following statements are TRUE concerning this laboratory exercise - The systematic identification of an organic com

Answer:

a. H₂O (conjugate acid); b. OH⁻ (conjugate base), H₃O⁺ (conjugate acid); c. H₂CO₃ (conjugate acid), CO₃⁻² (conjugate base); d. NH₄⁺ (conjugate strong acid) e. H₂SO₄ (conjugate acid), SO₄⁻² (conjugate base); f. No conjugate acid or base exists; g. H₂S (conjugate acid), S⁻² (conjugate base);

h. H₄N₂ (conjugate base)

Explanation:

a. OH⁻ + H⁺ ⇄ H₂O

The hydroxide functions as a Bronsted-Lowry base, allowing it to capture a proton, thus water serves as the conjugate acid.

b. H₂O is amphoteric, capable of acting as either an acid or a base. As a base, its conjugate acid is H₃O⁺, whereas as an acid, its conjugate base is OH⁻.

c. HCO₃⁻ + H⁺ ⇄ H₂CO₃

HCO₃⁻ + H₂O ⇄ CO₃⁻² + H₃O⁺

Bicarbonate is also amphoteric. When it captures a proton, it forms carbonic acid as the conjugate acid when acting as a base. When HCO₃⁻ acts as an acid and releases a proton, carbonate becomes the conjugate base.

d. Ammonia functions as a weak base, with ammonium being the conjugate strong acid.

NH₃ + H₂O ⇄ NH₄⁺ + OH⁻

e. Another amphoteric compound. Acid sulfate can function as both an acid and a base.

(similar to bicarbonate). Acting as a base yields sulfuric acid as the conjugate acid, while acting as an acid leads to sulfate as the conjugate base.

HSO₄⁻ + H₂O ⇄ SO₄⁻² + H₃O⁺

HSO₄⁻ + H⁺ ⇄ H₂SO₄

f. H₂O₂ does not accept H⁺ or OH⁻ nor does it expel H⁺. It’s neutral and does not function as an acid or base.

g. HS⁻ is amphoteric.

HS⁻ + H⁺ ⇄ H₂S

HS⁻ + H₂O ⇄ S⁻² + H₃O⁺

This is similar to the case of bicarbonate or acid sulfate.

h. H₅N₂⁺ + H₂O ⇄ H₄N₂ + H₃O⁺

Hydrazinium acts as an acid, making hydrazine its conjugate base.

Answer:

For A: The change in free energy for the reaction is -5339.76 J/mol

For B: Free energy change is expressed in kJ/mol

For C: The forward reaction favors progression, while the reverse reaction does not.

Explanation:

Regarding the specified chemical reaction:

• For A:

The relationship between standard Gibbs free energy and equilibrium constant is as follows:

The free energy change can be calculated using the following equation:

Or,

where,

= Change in free energy

R = Gas constant =

= standard temperature =

T = temperature of the cell =

= equilibrium constant =

Q = reaction quotient =

= 0.06 M

[DHAP] = 0.125 M

Substituting the values into the equation yields:

Thus, the change in free energy for the reaction is -5339.76 J/mol

• For B:

To convert the free energy change to kilojoules, we apply the conversion factor:

1 kJ = 1000 J

So,

Consequently, the free energy change's units are kJ/mol

• For C:

For spontaneity in the reaction, the Gibbs free energy must be negative. However, the calculations indicate a positive Gibbs free energy, leading to the conclusion that the reaction is not spontaneous.

The free energy change of the reaction is negative.

Consequently, the forward reaction is favored and the reverse reaction is not favored.

Answer:

Wood

Explanation:

Response:

The alteration in color.

Explanation:

The apple browns due to the oxidation process. This occurs when oxygen and water molecules from the air interact with it, resulting in oxidation. The oxidation process is notably rapid at room temperature.

For instance, if the peeled apple is placed in the refrigerator, it takes longer to oxidize and turn brown, but if left at room temperature, it quickly turns brown.

When oxygen interacts with the peeled apple, it activates the polyphenol oxidase enzyme, oxidizing the phenolic compounds and forming quinones, which then react with amino acids to create the brown coloration.