Question

Question
1
Question
2
A)
Which statement explains the relationship between the amount of energy it takes to break a bondand the amount of energy released when the same bond is formed?
(1 point)
The amount of energy it takes to break a bond is always less than the amount of energy released when the
bond is formed.
The amounts of energy are always equal.
The amount of energy it takes to break a bond is always greater than the amount of energy released when
the bond is formed.
The relationship depends on the particular bond.
A)
Which fact must be true if a relationship is endothermic?
(1 point)
More bond energy is absorbed on the reactant side than released on the product side.
More energy is needed to form the bonds on the product side than to form the bonds on the reactant side.
The energy of each bond on the reactant side is greater than the energy of each bond on the product side.
The bond energy released by breaking the bonds in the reactants is greater than the bond energy used to
form the products.
Question
3
A)
Use the information in the table to answer the question.
Bond Between Atoms and TheirRespective Electronegativity
Bond
Bond Energy (
)
Hydrogen and iodine gases react to produce hydroiodic acid according to the reaction.
How much total bond energy in
is in the products of the reaction?
(1 point)
kJ/mol
H-I 297
H-H 435
I-I 151
H2 + I2 → 2HI
kJ/mol
594
453
448
297
Question
4
A)
Use the information in the table to answer the question.
Bond Between Atoms and TheirRespective Electronegativity
Bond
Bond Energy (
)
Hydrogen and chlorine gases react to produce hydrochloric acid according to the reaction.
How much total bond energy, in
, is in the products of the reaction?
(1 point)
kJ/mol
H–Cl 427
Cl–Cl 242
H–H 435
H2 + Cl2 → 2HCl
kJ/mol
435
427
677
854
Question
5
A)
Use the table to answer the question.
Bonds and Bond Energies for Given Reactions
Reaction
Bonds Present
Energy of Bonds Broken and Formed (kJ/mol)
Which reaction is endothermic?
(1 point)
C + O2 → CO2 O = O
2 C = O
499
1478
N2 + O2 → 2NO N ≡ N
O = O
2 N = O
946
499
1214
S + O2 → SO2 O = O
2 S = O
499
1044
2CO + O2 → 2CO2 2 C ≡ O
O = O
4 C = O
2148
499
2956
C + O2 → CO2
2CO + O2 → 2CO2
S + O2 → SO2
N2 + O2 → 2NO

Answer 1

Here are the answers with brief reasons:

Question 1
- Answer: The amounts of energy are always equal.
- Reason: Breaking a bond requires the same amount of energy that is released when that same bond is formed (opposite in sign).

Question 2
- Answer: More bond energy is absorbed on the reactant side than released on the product side.
- Reason: An endothermic reaction absorbs net energy, so energy required to break reactant bonds > energy released forming product bonds.

Question 3
- Answer: 594 kJ/mol.
- Reason: Products are 2 HI bonds: 2 × 297 kJ/mol = 594 kJ/mol.

Question 4
- Answer: 854 kJ/mol.
- Reason: Products are 2 H–Cl bonds: 2 × 427 kJ/mol = 854 kJ/mol.

Question 5
- Answer: N2 + O2 → 2NO is endothermic.
- Reason: Bonds broken (N≡N 946 + O=O 499 = 1445 kJ) > bonds formed (2 N=O = 1214 kJ), so net energy absorbed.