To examine the reaction \( \text{C}_2\text{H}_4 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \), we need to check if it is balanced and then identify how many bonds are broken and how many are formed.
Step 1: Balancing the Reaction
On the left side:
- \( \text{C}_2\text{H}_4 \) has 2 carbon atoms and 4 hydrogen atoms.
- \( \text{O}_2 \) has 2 oxygen atoms.
On the right side:
- Each \( \text{CO}_2 \) has 1 carbon and 2 oxygens. For 2 \( \text{CO}_2 \), we have 2 carbon atoms and 4 oxygen atoms in total.
- Each \( \text{H}_2\text{O} \) has 2 hydrogen atoms. We need 2 \( \text{H}_2\text{O} \) for a total of 4 hydrogen atoms.
So, the balanced equation is: \[ \text{C}_2\text{H}_4 + 3\text{O}_2 \rightarrow 2\text{CO}_2 + 2\text{H}_2\text{O} \]
Step 2: Identify Bonds Broken and Formed
Bonds Broken:
- In \( \text{C}_2\text{H}_4 \), there are:
- 4 C–H bonds
- 1 C=C bond
- In \( 3\text{O}_2 \):
- 3 O=O bonds
Thus, the total the bonds broken are:
- 4 C–H
- 1 C=C
- 3 O=O
Total broken = 4 + 1 + 3 = 8 bonds broken.
Bonds Formed:
- In \( 2\text{CO}_2 \):
- Each CO2 has 2 C=O bonds, for a total of \( 2 \times 2 = 4 \) C=O bonds.
- In \( 2\text{H}_2\text{O} \):
- Each \( H_2O \) has 2 O–H bonds, for a total of \( 2 \times 2 = 4 \) O–H bonds.
Thus, the total bonds formed are:
- 4 C=O
- 4 O–H
Total formed = 4 + 4 = 8 bonds formed.
Conclusion:
So the answer is:
- Bonds broken: 4 C–H, 1 C=C, and 3 O=O bonds
- Bonds formed: 4 C=O and 4 O–H bonds
The correct response choice is: Four C–H, one C=C, and three O=O bonds need to break up. Four C=O and four O–H bonds need to form.