Which statement explains the relationship between the amount of energy it takes to break a bond and the amount of energy released when the same bond is formed

Responses:

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 amounts of energy are always equal.

The relationship depends on the particular bond.

The amount of energy it takes to break a bond is always less than the amount of energy released when the bond is formed.

11 answers

The correct response is:

The amounts of energy are always equal.

When a chemical bond is broken, energy is absorbed, and when a bond is formed, the same amount of energy is released. Thus, the energy required to break a bond is equal to the energy released when that bond is formed, though the actual values can vary depending on the specific bonds involved.

Which fact must be true if a relationship is endothermic
Responses:

The energy of each bond on the reactant side is greater than the energy of each bond 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.

More bond energy is absorbed on the reactant side than released 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.

The correct response is:

More bond energy is absorbed on the reactant side than released on the product side.

In an endothermic reaction, the total energy absorbed to break bonds in the reactants is greater than the total energy released when bonds are formed in the products. This results in a net absorption of energy, which characterizes the endothermic process.

Use the information in the table to answer the question.
Bond Bond Energy ( kJ/mol )
H-I 297
H-H 435
I-I 151
Hydrogen and iodine gases react to produce hydroiodic acid according to the reaction
H2+I2→2HI
How much total bond energy in kJ/mol is in the products of the reaction?
Responses:

448

594

297

453

To calculate the total bond energy in the products of the reaction \( \text{H}_2 + \text{I}_2 \rightarrow 2\text{HI} \), we need to consider the bond energy of hydrogen iodide (HI).

From the given information:

  • The bond energy of H-I is \( 297 , \text{kJ/mol} \).

Since 2 moles of HI are produced in the reaction, the total bond energy for the products (which consist of two HI bonds) is calculated as follows:

\[ \text{Total bond energy in products} = 2 \times \text{Bond Energy of HI} = 2 \times 297 , \text{kJ/mol} = 594 , \text{kJ/mol} \]

Therefore, the total bond energy in the products of the reaction is:

594.

Use the information in the table to answer the question.
Bond Bond Energy ( kJ/mol )
H–Cl 427
Cl–Cl 242
H–H 435
Hydrogen and chlorine gases react to produce hydrochloric acid according to the reaction.
H2+Cl2→2HCl
How much total bond energy, in kJ/mol , is in the products of the reaction
Responses:

435

427

854

677

To calculate the total bond energy in the products of the reaction \( \text{H}_2 + \text{Cl}_2 \rightarrow 2 \text{HCl} \), we need to determine the bond energy for hydrochloric acid (HCl) and then calculate the total bond energy for 2 moles of HCl.

From the provided information:

  • The bond energy of H–Cl is \( 427 , \text{kJ/mol} \).

Since 2 moles of HCl are produced in the reaction, we can calculate the total bond energy in the products as follows:

\[ \text{Total bond energy in products} = 2 \times \text{Bond Energy of HCl} = 2 \times 427 , \text{kJ/mol} = 854 , \text{kJ/mol} \]

Therefore, the total bond energy in the products of the reaction is:

854.

Use the table to answer the question.
Reaction Bonds Present Energy of Bonds Broken and Formed (kJ/mol)
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

Which reaction is endothermic?

Responses

N2+O2→2NO

2CO+O2→2CO2

S+O2→SO2

C + O2→CO2

To determine which reaction is endothermic, we need to compare the total energy of the bonds broken to the total energy of the bonds formed for each reaction. A reaction is classified as endothermic when the energy required to break the bonds is greater than the energy released when new bonds are formed.

Let's analyze each reaction with the provided energy values:

  1. C + O2 → CO2

    • Bonds broken: O=O (499 kJ/mol)
    • Bonds formed: 2 C=O (1478 kJ/mol)
    • Total energy of bonds broken = 499 kJ/mol
    • Total energy of bonds formed = 1478 kJ/mol
    • \( 499 < 1478 \) (Exothermic)
  2. N2 + O2 → 2NO

    • Bonds broken: N≡N (946 kJ/mol) + O=O (499 kJ/mol)
    • Bonds formed: 2 N=O (1214 kJ/mol)
    • Total energy of bonds broken = 946 + 499 = 1445 kJ/mol
    • Total energy of bonds formed = 1214 kJ/mol
    • \( 1445 > 1214 \) (Endothermic)
  3. S + O2 → SO2

    • Bonds broken: O=O (499 kJ/mol)
    • Bonds formed: 2 S=O (1044 kJ/mol)
    • Total energy of bonds broken = 499 kJ/mol
    • Total energy of bonds formed = 1044 kJ/mol
    • \( 499 < 1044 \) (Exothermic)
  4. 2CO + O2 → 2CO2

    • Bonds broken: 2 C≡O (2148 kJ/mol) + O=O (499 kJ/mol)
    • Bonds formed: 4 C=O (2956 kJ/mol)
    • Total energy of bonds broken = 2148 + 499 = 2647 kJ/mol
    • Total energy of bonds formed = 2956 kJ/mol
    • \( 2647 < 2956 \) (Exothermic)

Given this analysis, the only reaction that qualifies as endothermic is:

N2 + O2 → 2NO

What are explicit meanings?
Responses:
information in a text that support an idea or analysis

ideas or details that are stated directly in a text

conclusions readers form from evidence and reasoning

claims that are made during an analysis of a text

The correct response is:

ideas or details that are stated directly in a text.

Explicit meanings refer to information that is clearly stated and easily identifiable within the text, as opposed to implicit meanings, which require interpretation or inference.