One of the molecular orbitals of the H2- ion is sketched below: (a) Is the molecular orbital a σ or π MO? Is it bonding orantibonding? (b) In H2-, how many electrons occupy theMO shown above? (c) What is the bond order in the H2-ion? (d) Compared to the H—H bond in H2, the H—Hbond in H2- is expected to be which of the following:(i) Shorter and stronger, (ii) longer and stronger, (iii) shorterand weaker, (iv) longer and weaker, or (v) the same lengthand strength?

Explain in terms of bonding theory why all four hydrogen atoms of allene, H2CCCH2, cannot lie in the same plane.

The structure of amphetamine, a stimulant, is shown below. (Replacing one H atom on the NH2, or amino, group with CH3 gives methamphetamine a particularly dangerous drug commonly known as speed.) (a) What are the hybrid orbitals used by the C atoms of the C6 ring. by the C atoms of the side chain, and by the N atom? (b) Give approximate values for the bond angles A, B, and C. (c) How many bonds and bonds are in the molerule? (d) Is the molecule polar or nonpolar? (e) Amphetamine reacts readily with a proton (H+) in aqueous solution. Where does this proton attach to the molecule? Explain how the electrostatic potential map predicts this site of protonation.

trans-tetrazene (N4H4) consists of a chain of four nitrogen atoms with each of the two end atoms bonded to two hydrogen atoms. Use the concepts of steric number and hybridization to predict the overall geometry of the molecule. Give the expected structure of cis-tetrazene.

Which of the following statements is/are true? Correct the false statements. a. The molecules SeS3. SeS2, PCl5, TeCl4, ICl3, and XeCl2 all exhibit at least one bond angle which is approximately 120. b. The bond angle in SO2 should be similar to the bond angle in CS2 or SCI2. c. Of the compounds CF4, KrF4, and SeF4, only SeF4 exhibits an overall dipole moment (is polar). d. Central atoms in a molecule adopt a geometry of the bonded atoms and lone pairs about the central atom in order to maximize electron repulsions.

The diagram that follows shows the highest-energy occupiedMOs of a neutral molecule CX, where element X is in thesame row of the periodic table as C. (a) Based on the numberof electrons, can you determine the identity of X? (b) Wouldthe molecule be diamagnetic or paramagnetic? (c) Considerthe p2p MOs of the molecule. Would you expect them to havea greater atomic orbital contribution from C, have a greateratomic orbital contribution from X, or be an equal mixtureof atomic orbitals from the two atoms?

I wonder (d) below. Carbon monoxide is produced by incomplete combustion offossil fuels.(a) Give the electron configuration for the valence molecular orbitals of CO. The orbitals have the same energyorder as those of the N2 molecule.(b) Do you expect CO to be paramagnetic or diamagnetic?(c) What is the bond order of CO? Does this match thebond order predicted by the electron-dot structure?(d) CO can react with OH- to form the formate ion,HCO2-. Draw an electron-dot structure for the formateion, and give any resonance structures if appropriate. Thanks:)

(a) Sketch the molecular orbitals of the H2- ion and draw itsenergy-level diagram. (b) Write the electron configuration ofthe ion in terms of its MOs. (c) Calculate the bond order inH2-. (d) Suppose that the ion is excited by light, so that anelectron moves from a lower-energy to a higher-energy molecularorbital. Would you expect the excited-state H2- ion to bestable? (e) Which of the following statements about part (d) is correct: (i) The light excites an electron from a bonding orbitalto an antibonding orbital, (ii) The light excites an electronfrom an antibonding orbital to a bonding orbital, or (iii)In the excited state there are more bonding electrons thanantibonding electrons?

(a) If the valence atomic orbitals of an atom are sp hybridized,how many unhybridized p orbitals remain in thevalence shell? How many π bonds can the atom form?(b) Imagine that you could hold two atoms that are bondedtogether, twist them, and not change the bond length.Would it be easier to twist (rotate) around a single σ bondor around a double (σ plus π) bond, or would they be thesame?

Ethyl acetate, C4H8O2, is a fragrant substance used both as asolvent and as an aroma enhancer. Its Lewis structure is (a) What is the hybridization at each of the carbon atomsof the molecule? (b) What is the total number of valenceelectrons in ethyl acetate? (c) How many of the valence electronsare used to make s bonds in the molecule? (d) Howmany valence electrons are used to make p bonds? (e) Howmany valence electrons remain in nonbonding pairs in themolecule?