Question 1

Find incorrect statement regarding low reactivity of O₂ molecule. A) It has a high bond energy. B) Its electronic configuration does not allow for Lewis acid/base reactivity. C) It easily forms stable complexes that impede any further reactivity.

Accepted Answer

The incorrect statement is C) It easily forms stable complexes that impede any further reactivity. This is incorrect because the molecule in question, O₂ (Osmium diboride), is known for its high bond energy and stability rather than forming stable complexes that would impede further reactivity. Its low reactivity is primarily due to the high bond energy and electronic configuration, not because it forms stable complexes.

Question 2

Which of the following is not an industrial process for isolation of elemental sulfur:&#10;A) Oswald process&#10;B) Frasch process&#10;C) Claus process

Accepted Answer

The Oswald process is not an industrial process for the isolation of elemental sulfur. The Frasch process and the Claus process are both well-known methods for sulfur extraction. The Frasch process involves melting sulfur underground and pumping it to the surface, while the Claus process is used to recover sulfur from gaseous hydrogen sulfide found in natural gas and petroleum refining processes.

Question 3

A steady increase in boiling points for hydrides of sulfur, selenium and tellurium can be attributed to:&#10;A) A decrease in vapour pressure&#10;B) An increase in molecular weight&#10;C) A decrease in hydrogen bond strength.

Accepted Answer

The boiling points of hydrides of sulfur, selenium, and tellurium increase due to an increase in molecular weight, which leads to stronger London dispersion forces between molecules.

Question 4

Which of the following species has the longest O-O bond: (i) O₂ (ii) O₂^- (iii) O₂^2- A) (i) B) (ii) C) (iii)

Accepted Answer

(iii) has the longest O-O bond due to the presence of peroxide linkage (-O-O-) which generally has longer O-O bonds compared to other oxygen-containing functional groups.

Question 5

Which metals form disulfides with layered structure?&#10;A) 4d metals&#10;B) 3d metals&#10;C) s block metals

Accepted Answer

4d metals, such as molybdenum and tungsten, form layered disulfides like MoS2 and WS2, which have a layered structure.

Question 6

Find correct statement(s) about sulfur oxides:
(i) SO₂ is neither a Lewis acid nor a Lewis base.
(ii) Both SO₂ and SO₃ are acidic oxides.
(iii) SO₂ is produced on a large scale in industry.

A) (i) and (ii)
B) (iii) only
C) (ii) and (iii)

Accepted Answer

(ii) Both SO2 and SO3 are acidic oxides, reacting with water to form sulfurous and sulfuric acids, respectively. (iii) SO2 is produced on a large scale in industry, primarily from the burning of fossil fuels and the smelting of mineral ores that contain sulfur.

Question 7

If a mixture of H₂S₂O₇ and H₂SO₄ contains HS₂O₇^- and H₃SO₄⁺, what can be concluded about relative strengths of these two acids: A) H₂SO₄ is a stronger acid than H₂S₂O₇ B) H₂SO₄ is a weaker acid than H₂S₂O₇ C) H₂S₂O₇ is more basic than H₂SO₄

Accepted Answer

The presence of HS₂O₇^- and H₃SO₄⁺ indicates that the first acid donates a proton (H+) to form a negative ion (^-), while the second acid gains a proton to form a positive ion (⁺). This suggests that the first acid is stronger because it donates a proton more readily, making the second acid weaker in comparison.

Question 8

Which of the following acids is an example of a polythionic acid? A) H₂S₂O₇. B) H₂S₆O₆. C) H₂S₂

Accepted Answer

Polythionic acids have the general formula H2SxO6, where x is greater than 2. Choice B, which translates to H2S6O6, fits this description, making it an example of a polythionic acid.

Question 9

Which polyanions frequently have bicyclic structures?&#10;A) Polysulfides.&#10;B) Polyselenides.&#10;C) Polytellurides.

Accepted Answer

Polytellurides are known to form bicyclic structures due to the ability of tellurium atoms to form intramolecular bonds.

Question 10

Both S₄N₄ and S₂N₂ are: A) thermodynamically unstable B) common precursors for sulfur chemistry in low oxidation states C) easy to handle.

Accepted Answer

These compounds are thermodynamically unstable, which means they are highly reactive and can decompose or react easily under certain conditions. This instability is due to their high energy content or structural strain.

Deck 16: The Group 16 Elements