Question
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)
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?
(1 point)
Responses
N2+O2→2NO
N sub 2 plus O sub 2 rightarrow 2 N O
C + O2→CO2
C plus O sub 2 rightarrow C O sub 2
S+O2→SO2
S plus O sub 2 rightarrow S O sub 2
2CO+O2→2CO2
Bonds and Bond Energies for Given Reactions
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?
(1 point)
Responses
N2+O2→2NO
N sub 2 plus O sub 2 rightarrow 2 N O
C + O2→CO2
C plus O sub 2 rightarrow C O sub 2
S+O2→SO2
S plus O sub 2 rightarrow S O sub 2
2CO+O2→2CO2
Answers
GPT-4o mini
To determine which reaction is endothermic, we need to look at the total bond energies for bonds broken and formed.
An endothermic reaction absorbs energy, which means that the total energy of the bonds broken is greater than the total energy of the bonds formed.
Let's calculate the total energy for each reaction.
1. **N2 + O2 → 2NO**
- Bonds broken: N≡N (946 kJ/mol) + O=O (499 kJ/mol) = 1445 kJ/mol
- Bonds formed: 2 N=O (1214 kJ/mol each) = 2 × 1214 kJ/mol = 2428 kJ/mol
- Total change = Bonds broken - Bonds formed = 1445 - 2428 = -983 kJ/mol (exothermic)
2. **C + O2 → CO2**
- Bonds broken: O=O (499 kJ/mol) = 499 kJ/mol
- Bonds formed: 2 C=O (1478 kJ/mol) = 2 × 1478 kJ/mol = 2956 kJ/mol
- Total change = 499 - 2956 = -2457 kJ/mol (exothermic)
3. **S + O2 → SO2**
- Bonds broken: O=O (499 kJ/mol) = 499 kJ/mol
- Bonds formed: 2 S=O (1044 kJ/mol each) = 2 × 1044 kJ/mol = 2088 kJ/mol
- Total change = 499 - 2088 = -1589 kJ/mol (exothermic)
4. **2CO + O2 → 2CO2**
- Bonds broken: 2 C≡O (2148 kJ/mol) + O=O (499 kJ/mol) = 2148 + 499 = 2647 kJ/mol
- Bonds formed: 4 C=O (1478 kJ/mol each) = 4 × 1478 kJ/mol = 5912 kJ/mol
- Total change = 2647 - 5912 = -3265 kJ/mol (exothermic)
Each of these reactions is exothermic (they all release energy). However, to check if any of them are endothermic, we would expect the energy of bonds formed to be less than those broken, indicating absorption of energy (positive total change).
Based on the calculations, none of the reactions listed are endothermic. They are all exothermic. If we need to select from the given options under the context of the question, then it's correct to conclude that none of the provided reactions are endothermic.
An endothermic reaction absorbs energy, which means that the total energy of the bonds broken is greater than the total energy of the bonds formed.
Let's calculate the total energy for each reaction.
1. **N2 + O2 → 2NO**
- Bonds broken: N≡N (946 kJ/mol) + O=O (499 kJ/mol) = 1445 kJ/mol
- Bonds formed: 2 N=O (1214 kJ/mol each) = 2 × 1214 kJ/mol = 2428 kJ/mol
- Total change = Bonds broken - Bonds formed = 1445 - 2428 = -983 kJ/mol (exothermic)
2. **C + O2 → CO2**
- Bonds broken: O=O (499 kJ/mol) = 499 kJ/mol
- Bonds formed: 2 C=O (1478 kJ/mol) = 2 × 1478 kJ/mol = 2956 kJ/mol
- Total change = 499 - 2956 = -2457 kJ/mol (exothermic)
3. **S + O2 → SO2**
- Bonds broken: O=O (499 kJ/mol) = 499 kJ/mol
- Bonds formed: 2 S=O (1044 kJ/mol each) = 2 × 1044 kJ/mol = 2088 kJ/mol
- Total change = 499 - 2088 = -1589 kJ/mol (exothermic)
4. **2CO + O2 → 2CO2**
- Bonds broken: 2 C≡O (2148 kJ/mol) + O=O (499 kJ/mol) = 2148 + 499 = 2647 kJ/mol
- Bonds formed: 4 C=O (1478 kJ/mol each) = 4 × 1478 kJ/mol = 5912 kJ/mol
- Total change = 2647 - 5912 = -3265 kJ/mol (exothermic)
Each of these reactions is exothermic (they all release energy). However, to check if any of them are endothermic, we would expect the energy of bonds formed to be less than those broken, indicating absorption of energy (positive total change).
Based on the calculations, none of the reactions listed are endothermic. They are all exothermic. If we need to select from the given options under the context of the question, then it's correct to conclude that none of the provided reactions are endothermic.