Question

The stretch for a C-H bond where the carbon is sp2 hybridized would be located where on an IR spectrum? (1 pt) at approximately 3300 cm-1 just below 3000 cm-1 just above 3000 cm-1 at approximately 2700 cm-1

Answer 1

Answer:

Just above of 3000 $cm^{-1}$

Explanation:

The strength of C-H bond determines the position of the C-H stretching vibration peak higher strength leads to higher wavenumber.

C atoms sp hybridized (triple bond between carbon atoms) have more sigma character in their bonds (there are less p orbitals involved), hence their bonds are stronger. The C-H stretching of sp hybridized carbon are around 3300 $cm^{-1}$.

C atoms sp$^{3}$ hybridized (single bond between carbon atoms) have less sigma character in their bonds (there are more p orbitals involved), hence their bond are weaker. The C-H stretching of C sp$^{3}$ hybridized are around 2900 $cm^{-1}$.

C atoms sp$^{2}$ hybridized (double bond between carbon atoms) have less sigma character than sp atoms, but more sigma character than sp$^{3}$ atoms in their bonds. Hence their bonds have intermediate strength. The C-H stretching of C sp$^{2}$ hybridized are around 3100 $cm^{-1}$.