Question

sos

1. The O-C-O bond angle in the CO32-ion is approximately A. 90° B. 109.5 Trigonal geometry (C.)120° D. 180° E. 60° will have bond angles of 109° 2. Of the following species, A. PO4 B. CIF3 C. CCl4 D. NH3 E. All of these will have bond angles of 1090 3. The basis of the VSEPR model of molecular bonding is A. regions of electron density on an atom will organize themselves so as to maximize s-character B. regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap C. atomic orbitals of the bonding atoms must overlap for a bond to form D. electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions E. hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry 4. Resonance structures differ by A. number and placement of electrons B. number of electrons only C. placement of atoms only D. number of atoms only E.placement of electrons only

Answer 1

Question 1.

The answer is option C.

Explanation: The bond angle in trigonal planar geometry is 120^o.

Question 2.

The answer is both option A and option C.

Explanation: PO₄^3- and CCl₄ have perfect tetrahedron geometry, so the bond angle in them is 109.5^o.

Question 3.

The answer is option B.

Explanation: Valence Shell Electron Pair Repulsion (VSEPR) theory clearly states that the regions of electron density on an atom will organize themselves so as to maximize overlap.

Question 4.

The answer is option E.

Explanation: Resonance structures arise by delocalization of electrons, i.e. they differ by the placement of electrons only.