The bond energy for a C-H bond is about 413 kJ/mol in CH, but 380 kJ/mol in CHB33. Although these values are relatively close in magnitude, they are different. Explain why they are different. Does the fact that the bond energy is lower in CHB33 make any sense? Why?

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### Bond Energy Comparison Between CH₄ and CHBr₃

The bond energy for a carbon-hydrogen (C—H) bond is approximately 413 kJ/mol in methane (CH₄), while it is about 380 kJ/mol in bromoform (CHBr₃). Although these values are relatively close, they are not identical. Here, we explore the reasons for this difference and whether the lower bond energy in CHBr₃ makes sense.

#### Explanation

1. **Electronegativity and Bond Strength:**
   - In methane, the C—H bond is surrounded by hydrogen atoms, which do not significantly alter the electronegativity around the carbon compared to bromine in CHBr₃.
   - Bromine is more electronegative than hydrogen, which affects the electron distribution and overall bond strength in CHBr₃, slightly reducing the bond energy.

2. **Steric Effects:**
   - The larger size of bromine atoms in CHBr₃ can lead to increased steric strain compared to the smaller hydrogen atoms in CH₄.
   - This strain can weaken the bond, resulting in a lower bond energy.

3. **Inductive Effects:**
   - The presence of bromine, a halogen, can cause inductive effects that make it easier for the C—H bond in CHBr₃ to break compared to that in methane.

#### Conclusion

The lower bond energy in CHBr₃ compared to CH₄ is consistent with the influences of electronegativity, steric effects, and inductive effects exerted by the bromine atoms. These factors collectively contribute to the observed difference, making the lower bond energy in CHBr₃ a reasonable expectation.
Transcribed Image Text:### Bond Energy Comparison Between CH₄ and CHBr₃ The bond energy for a carbon-hydrogen (C—H) bond is approximately 413 kJ/mol in methane (CH₄), while it is about 380 kJ/mol in bromoform (CHBr₃). Although these values are relatively close, they are not identical. Here, we explore the reasons for this difference and whether the lower bond energy in CHBr₃ makes sense. #### Explanation 1. **Electronegativity and Bond Strength:** - In methane, the C—H bond is surrounded by hydrogen atoms, which do not significantly alter the electronegativity around the carbon compared to bromine in CHBr₃. - Bromine is more electronegative than hydrogen, which affects the electron distribution and overall bond strength in CHBr₃, slightly reducing the bond energy. 2. **Steric Effects:** - The larger size of bromine atoms in CHBr₃ can lead to increased steric strain compared to the smaller hydrogen atoms in CH₄. - This strain can weaken the bond, resulting in a lower bond energy. 3. **Inductive Effects:** - The presence of bromine, a halogen, can cause inductive effects that make it easier for the C—H bond in CHBr₃ to break compared to that in methane. #### Conclusion The lower bond energy in CHBr₃ compared to CH₄ is consistent with the influences of electronegativity, steric effects, and inductive effects exerted by the bromine atoms. These factors collectively contribute to the observed difference, making the lower bond energy in CHBr₃ a reasonable expectation.
### Properties of Ionic Compounds

Some of the important properties of ionic compounds are as follows:

1. **Low electrical conductivity as solids and high conductivity in solution or when molten.**
2. **Relatively high melting and boiling points.**
3. **Brittleness.**
4. **Solubility in polar solvents.**

How does the concept of ionic bonding discussed in this chapter account for these properties?
Transcribed Image Text:### Properties of Ionic Compounds Some of the important properties of ionic compounds are as follows: 1. **Low electrical conductivity as solids and high conductivity in solution or when molten.** 2. **Relatively high melting and boiling points.** 3. **Brittleness.** 4. **Solubility in polar solvents.** How does the concept of ionic bonding discussed in this chapter account for these properties?
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