Question 1

How many equivalent resonance structures can be drawn for the molecule of SO₃ without having to violate the octet rule on the sulfur atom?

Accepted Answer

The molecule SO₃, when interpreted correctly as SO3, has three equivalent resonance structures. These structures involve the sulfur atom double-bonded to each of the three oxygen atoms in turn, with the other two oxygens carrying a negative charge and the sulfur atom having a formal positive charge. This arrangement allows for the depiction of the delocalized pi electrons among the sulfur and oxygen atoms without violating the octet rule for sulfur.

Question 2

Using the table of bond dissociation energies,the ΔH for the following gas-phase reaction is ________ kJ.

Accepted Answer

The answer of Using the table of bond dissociation energies,the...

Question 3

Using the table of average bond energies below,the △H for the reaction is ________ kJ. H₃C-O-H (g)→ C≡O (g)+ 2H₂ (g) Bond: C-O C=O C≡O C-H H-H O-H D (kJ/mol): 358 799 1072 413 436 463

Accepted Answer

The answer of Using the table of average bond energies...

Question 4

Using the table of bond dissociation energies,the ΔH for the following reaction is ________ kJ. 2HCl (g)+ F₂ (g)→ 2HF (g)+ Cl₂ (g)

Accepted Answer

The answer of Using the table of bond dissociation energies,the...

Question 5

In the Lewis structure of HCO₃^-,the formal charge on H is ________,and the formal charge on C is ________.

Accepted Answer

The formal charge on an atom in a molecule can be calculated using the formula: Formal charge = (Valence electrons) - (Non-bonding electrons) - 1/2(Bonding electrons). For hydrogen (H), it typically has 1 valence electron, forms 1 bond, and has no lone pairs, leading to a formal charge of 0. For carbon (C), it has 4 valence electrons, forms 4 bonds in this molecule (assuming a typical bonding scenario for a Lewis structure involving C, H, O, and S), and has no lone pairs, leading to a formal charge of 0 as well.

Question 6

The formal charge on sulfur in SO₄^2- is ________,where the Lewis structure of the ion is:

Accepted Answer

The answer of The formal charge on sulfur in SO₄^2-...

Question 7

In the Lewis structure of ClF,the formal charge on Cl is ________,and the formal charge on F is ________.

Accepted Answer

In the Lewis structure of ClF, chlorine (Cl) and fluorine (F) form a single bond. Chlorine has 7 valence electrons and fluorine has 7 valence electrons. When they form a single bond, each contributes one electron to the bond, leaving chlorine and fluorine with 6 and 6 non-bonding electrons, respectively. The formal charge is calculated as the number of valence electrons in the free atom minus the number of non-bonding electrons minus half the number of bonding electrons. For both Cl and F, this calculation results in a formal charge of 0, indicating that both atoms have no formal charge in the ClF molecule.

Question 8

How many equivalent resonance forms can be drawn for the nitrate ion?

Accepted Answer

The nitrate ion has three equivalent resonance structures as shown below:
O
||
N=O
||
O-
O
||
N-O
||
O-
O
||
N=O
|
O-

Question 9

The ________ ion has a noble gas electron configuration.

Accepted Answer

The Cl^- ion has gained an electron to achieve the electron configuration of argon, a noble gas.

Question 10

How many equivalent resonance forms can be drawn for CO₃^2-? (Carbon is the central atom.)

Accepted Answer

The carbonate ion (CO₃²⁻) has three equivalent resonance forms. Each form has one of the oxygen atoms double-bonded to the carbon, while the other two oxygen atoms have single bonds and carry a negative charge. The double bond can be placed between the carbon and any of the three oxygen atoms, resulting in three equivalent structures.

Question 11

The Lewis structure of PF₃ shows that the central phosphorus atom has ________ nonbonding and ________ bonding electron pair(s).

Accepted Answer

Phosphorus in PFS (assuming a typo and it should be PF5) has 5 valence electrons. In PF5, all 5 electrons are used to form bonds with 5 fluorine atoms, leaving no nonbonding electrons on phosphorus. However, the question seems to contain a typo or encoding error (PF₃), which complicates direct interpretation. Assuming the intended molecule is PF5, based on typical valence and bonding patterns, phosphorus would have 1 nonbonding pair (due to the error in the question, but actually it should have 0) and 3 bonding pairs in a simplified or mistaken interpretation. However, correctly, PF5 has no nonbonding pairs and 5 bonding pairs. Given the options and likely errors in the question, the closest match under a misunderstanding would be 1 nonbonding and 3 bonding, but this does not accurately reflect PF5's structure. The response is based on interpreting the question's intent rather than accurate chemical principles due to the apparent errors.

Question 12

The formal charge on carbon in the molecule below is ________.

Accepted Answer

The answer of The formal charge on carbon in the...

Question 13

There are ________ paired and ________ unpaired electrons in the Lewis symbol for a fluorine atom.

Accepted Answer

Fluorine has 7 valence electrons: 6 of them form 3 pairs, and 1 remains unpaired, making the correct answer 6 paired and 1 unpaired.

Question 14

How many different types of resonance structures can be drawn for the ion SO₃^2-?

Accepted Answer

The ion described is sulfate (SO4^2-). For the sulfate ion, there are three major resonance structures that can be drawn, where the double bond between sulfur and oxygen atoms can be placed in different positions while the other oxygen atoms have single bonds to the sulfur atom.

Question 15

Using the table of average bond energies below,the ΔH for the reaction is ________ kJ. H-C≡C-H (g)+ H-Cl (g)→ H₂C CHCl (g) Bond: C≡C C=C H-Cl C-Cl C-H D (kJ/mol): 839 614 431 328 413

Accepted Answer

To calculate the ΔH for the reaction, we need to calculate the total bond energies of the bonds broken and the bonds formed.

Bonds Broken:
1 H-C≡C bond = 839 kJ/mol
1 H-Cl bond = 431 kJ/mol

Bonds Formed:
1 C-H bond = 413 kJ/mol
1 C-Cl bond = 328 kJ/mol
1 C=C bond = 614 kJ/mol

Total Bond Energies Broken - Total Bond Energies Formed = ΔH
(1 x 839) + (1 x 431) - (1 x 413) - (1 x 328) - (1 x 614) = -85 kJ/mol

Therefore, the answer is B) -85.

Question 16

The formal charge on nitrogen in NO₃^- is ________,where the Lewis structure of the ion is:

Accepted Answer

To calculate the formal charge on nitrogen in NO₃^-: Formal charge = valence electrons - (number of lone pair electrons + 1/2 * number of bonding electrons) Valence electrons of nitrogen = 5 Number of lone pairs on nitrogen = 2 Number of bonding electrons between nitrogen and oxygen = 3 Formal charge = 5 - (2 + 1/2 * 3) = +1 Therefore, the formal charge on nitrogen in NO₃^- is +1, and the answer is C.

Question 17

Using the table of bond dissociation energies,the ΔH for the reverse of following gas-phase reaction is ________ kJ.

Accepted Answer

The answer of Using the table of bond dissociation energies,the...

Question 18

In the resonance form of ozone shown below,the formal charge on the central oxygen atom is ________.

Accepted Answer

The answer of In the resonance form of ozone shown...

Question 19

Using the table of average bond energies below,the ΔH for the reaction is ________ kJ.  Bond: C≡C C-C H-I C-I C-H D (kJ/mol): 839 348 299 240 413

Accepted Answer

The bond dissociation energy (D) for HI is 299 kJ/mol, and that for H-Cl is 431 kJ/mol. Bond formation between I2 and Cl2 releases energy equal to the sum of the bond dissociation energies of H-I and Cl-Cl and the bond formation energy of I-Cl. 
ΔH = [2(D(Cl-Cl)) + D(H-I)] - D(I-Cl) 
ΔH = [2(431) + 299] - 240 = -217 kJ/mol
Therefore, the ΔH for the reaction is -217 kJ/mol. The best choice is C, which is the negative value closest to the calculated value.

Question 20

The ________ ion has a noble gas electron configuration.

Accepted Answer

Be²⁺ has a noble gas electron configuration because it has lost two electrons, leaving it with the same number of electrons as helium, which is a noble gas.

Quiz 8: Basic Concepts of Chemical Bonding

How many equivalent resonance structures can be drawn for the molecule of SO₃ without having to violate the octet rule on the sulfur atom?

Using the table of bond dissociation energies,the ΔH for the following gas-phase reaction is ________ kJ.

Using the table of average bond energies below,the △H for the reaction is ________ kJ. H₃C-O-H (g) → C≡O (g) + 2H₂ (g) Bond: C-O C=O C≡O C-H H-H O-H D (kJ/mol) : 358 799 1072 413 436 463

Using the table of bond dissociation energies,the ΔH for the following reaction is ________ kJ. 2HCl (g) + F₂ (g) → 2HF (g) + Cl₂ (g)

In the Lewis structure of HCO₃^-,the formal charge on H is ,and the formal charge on C is .

The formal charge on sulfur in SO₄^2- is ________,where the Lewis structure of the ion is:

In the Lewis structure of ClF,the formal charge on Cl is ,and the formal charge on F is .

How many equivalent resonance forms can be drawn for the nitrate ion?

The ________ ion has a noble gas electron configuration.

How many equivalent resonance forms can be drawn for CO₃^2-? (Carbon is the central atom.)

The Lewis structure of PF₃ shows that the central phosphorus atom has nonbonding and bonding electron pair(s) .

The formal charge on carbon in the molecule below is ________.

There are paired and unpaired electrons in the Lewis symbol for a fluorine atom.

How many different types of resonance structures can be drawn for the ion SO₃^2-?

Using the table of average bond energies below,the ΔH for the reaction is ________ kJ. H-C≡C-H (g) + H-Cl (g) → H₂C CHCl (g) Bond: C≡C C=C H-Cl C-Cl C-H D (kJ/mol) : 839 614 431 328 413

The formal charge on nitrogen in NO₃^- is ________,where the Lewis structure of the ion is:

Using the table of bond dissociation energies,the ΔH for the reverse of following gas-phase reaction is ________ kJ.

In the resonance form of ozone shown below,the formal charge on the central oxygen atom is ________.

Using the table of average bond energies below,the ΔH for the reaction is ________ kJ. Bond: C≡C C-C H-I C-I C-H D (kJ/mol) : 839 348 299 240 413

The ________ ion has a noble gas electron configuration.

Quiz 8: Basic Concepts of Chemical Bonding

How many equivalent resonance structures can be drawn for the molecule of SO3 without having to violate the octet rule on the sulfur atom?

Using the table of bond dissociation energies,the ΔH for the following gas-phase reaction is ________ kJ.

Using the table of average bond energies below,the △H for the reaction is ________ kJ. H3C-O-H (g) → C≡O (g) + 2H2 (g) Bond: C-O C=O C≡O C-H H-H O-H D (kJ/mol) : 358 799 1072 413 436 463

Using the table of bond dissociation energies,the ΔH for the following reaction is ________ kJ. 2HCl (g) + F2 (g) → 2HF (g) + Cl2 (g)

In the Lewis structure of HCO3-,the formal charge on H is ________,and the formal charge on C is ________.

The formal charge on sulfur in SO42- is ________,where the Lewis structure of the ion is:

In the Lewis structure of ClF,the formal charge on Cl is ________,and the formal charge on F is ________.

How many equivalent resonance forms can be drawn for the nitrate ion?

The ________ ion has a noble gas electron configuration.

How many equivalent resonance forms can be drawn for CO32-? (Carbon is the central atom.)

The Lewis structure of PF3 shows that the central phosphorus atom has ________ nonbonding and ________ bonding electron pair(s) .

The formal charge on carbon in the molecule below is ________.

There are ________ paired and ________ unpaired electrons in the Lewis symbol for a fluorine atom.

How many different types of resonance structures can be drawn for the ion SO32-?

Using the table of average bond energies below,the ΔH for the reaction is ________ kJ. H-C≡C-H (g) + H-Cl (g) → H2C CHCl (g) Bond: C≡C C=C H-Cl C-Cl C-H D (kJ/mol) : 839 614 431 328 413

The formal charge on nitrogen in NO3- is ________,where the Lewis structure of the ion is:

Using the table of bond dissociation energies,the ΔH for the reverse of following gas-phase reaction is ________ kJ.

In the resonance form of ozone shown below,the formal charge on the central oxygen atom is ________.

Using the table of average bond energies below,the ΔH for the reaction is ________ kJ. Bond: C≡C C-C H-I C-I C-H D (kJ/mol) : 839 348 299 240 413

The ________ ion has a noble gas electron configuration.

How many equivalent resonance structures can be drawn for the molecule of SO₃ without having to violate the octet rule on the sulfur atom?

Using the table of average bond energies below,the △H for the reaction is ________ kJ. H₃C-O-H (g) → C≡O (g) + 2H₂ (g) Bond: C-O C=O C≡O C-H H-H O-H D (kJ/mol) : 358 799 1072 413 436 463

Using the table of bond dissociation energies,the ΔH for the following reaction is ________ kJ. 2HCl (g) + F₂ (g) → 2HF (g) + Cl₂ (g)

In the Lewis structure of HCO₃^-,the formal charge on H is ,and the formal charge on C is .

The formal charge on sulfur in SO₄^2- is ________,where the Lewis structure of the ion is:

In the Lewis structure of ClF,the formal charge on Cl is ,and the formal charge on F is .

How many equivalent resonance forms can be drawn for CO₃^2-? (Carbon is the central atom.)

The Lewis structure of PF₃ shows that the central phosphorus atom has nonbonding and bonding electron pair(s) .

There are paired and unpaired electrons in the Lewis symbol for a fluorine atom.

How many different types of resonance structures can be drawn for the ion SO₃^2-?

Using the table of average bond energies below,the ΔH for the reaction is ________ kJ. H-C≡C-H (g) + H-Cl (g) → H₂C CHCl (g) Bond: C≡C C=C H-Cl C-Cl C-H D (kJ/mol) : 839 614 431 328 413

The formal charge on nitrogen in NO₃^- is ________,where the Lewis structure of the ion is: