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How many sigma and pi bonds are present in ethyne (C₂H₂)?
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Ethyne (C₂H₂) has 3 sigma bonds and 2 pi bonds.
What is a polar covalent bond and give an example from the lecture notes.
A polar covalent bond involves unequal sharing of electrons due to an electronegativity difference ≥ 0.5. An example is the C-F bond in methyl fluoride.
What is the difference between formal charges and actual charges in ions?
Formal charge is a theoretical charge based on valence electrons minus bonds and lone pairs. Actual charges are observed charges in ions due to electron gain or loss.
Describe the general formula for alkanes and give an example.
The general formula for alkanes is CₙH₂ₙ₊₂. An example is methane (CH₄).
What type of hybridization occurs in methane (CH₄), ethene (C₂H₄), and ethyne (C₂H₂)?
Methane (CH₄) exhibits sp³ hybridization, ethene (C₂H₄) exhibits sp² hybridization, and ethyne (C₂H₂) exhibits sp hybridization.
Explain why a C-F bond is considered polar while a C-H bond is considered non-polar.
A C-F bond is polar because the electronegativity difference is ≥ 0.5, leading to unequal sharing of electrons. A C-H bond is non-polar because the electronegativity difference is < 0.5, leading to equal sharing of electrons.
Compare the bond lengths of single, double, and triple bonds.
Single bonds are the longest (~154 pm), double bonds are shorter (~133 pm), and triple bonds are the shortest (~120 pm).
What is the defining characteristic of a radical in organic chemistry?
A radical has an odd number of electrons, making it highly reactive.
Describe which bonds in a compound are considered sigma bonds and which are considered pi bonds.
Single bonds are all sigma bonds. In double bonds, one is a sigma bond and one is a pi bond. In triple bonds, one is a sigma bond and two are pi bonds.
Explain the process to determine the hybridization of an atom within a molecule.
Count the number of groups (atoms + lone pairs) attached to the atom. Use sp³ for 4 groups, sp² for 3 groups, and sp for 2 groups.
Provide the structure and functional group of ethanol and explain its naming.
Ethanol (C₂H₅OH) contains an OH group (alcohol) attached to an ethyl (C₂H₅) chain.
What is the difference between sigma and pi bonds in terms of bond strength and structure?
Sigma bonds are stronger and form from the end-to-end overlap of orbitals, making single bonds. Pi bonds are weaker and form from the side-to-side overlap of orbitals, present in double and triple bonds.
What are the bonding preferences for carbon and nitrogen in organic compounds?
Carbon typically forms 4 bonds, while nitrogen forms 3 bonds.
What is the bond order for single, double, and triple bonds?
The bond order is 1 for single bonds, 2 for double bonds, and 3 for triple bonds.
Calculate the formal charge of an oxygen atom in a water molecule (H₂O).
The formal charge = Valence Electrons - (Bonds + Lone Pairs). For oxygen in H₂O: 6 - (2 + 4) = 0.
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