gen chem 2.3

Which of the following is the correct Lewis structure for BF3?

1) First find the total number of valence electrons: 3 + 3(7) = 24 electrons. 2) Next set up the molecular skeleton with the atom that can make the most bonds (boron in this case) in the middle. 3) Fill up the octets of the outer F atoms. 4) There are no electrons left at this point. 5) The central atom doesnt have a filled octet but recall that boron is one of the exceptions that is allowed to go under the octet rule with only 6 electrons.

How many lone pairs of electrons are around the Xe atom in XeF4? 1 2 3

2

How many lone pairs of electrons are on the central atom of IBr3? 1 2 3 4

2

Which of the following structures is a valid resonance contributor for N2O?

A

Which of the following is the correct Lewis structure for H2CO?

D 1) First find the total number of valence electrons: 4 + 6 + 2(1) = 12 electrons. 2) Next set up the molecular skeleton with the atom that can make the most bonds (carbon in this case) in the middle. 3) Fill up the octets of the outer oxygen atom. The hydrogen atoms are already full. 4) There are no electrons remaining. 5) The central carbon atom isnt happy and still needs 2 more electrons so well have the oxygen donate a lone pair and make a double bond to the carbon atom.

Which of the following molecules/ions is represented by 3 resonance structures? HClO2 PBr3 O3 CO NO3-

NO3- In looking for a molecule with 3 resonance structures we can probably start by looking to see which molecules/ions have 3 atoms around the central atom: only NO3- and PBr3 do. But PBr3 does not have resonance.