Select the reasons why the molecule BF3 is trigonal planar and a molecule with a similar formula, ClF3, is T-s

Question

Select the reasons why the molecule BF3 is trigonal planar and a molecule with a similar formula, ClF3, is T-shaped.

1. ClF3 has three bonding pairs and two lone pairs.
2. The electron-group geometry for ClF3 is trigonal bipyramidal.
3. BF3 has two bonding pairs and one lone pair.
4. BF3 has two electron groups.
5. BF3 has all bonding pairs

I know number one is right but I am not sure what else is. Help?

Answer 1

2 is right
5 is right

the other two (3 and 4) are incorrect statements.

Answer 2

I am an organic chemist familiar with the nature of DNA and other molecules. Almost all molecules in the world are the result of thermodynamics. A chemical system tends to go from a higher energy state to lower energy. There is more chemical energy locked up in an H-H bond than an O-H bond. so if you have a mixture of hydrogen (H2) and oxygen (O2), they will form more stable, lower energy bonds, and H-O-H or water is formed. Think of it as rocks on a hill. Rocks tend to go downhill. It's extremely rare for a rock to go uphill, but it will if you push it (put energy into the system). Some with molecules, they go "downhill" energetically. You can split water back into hydrogen and oxygen, but you need to add energy to the system. An electric current is needed to reform H2 and O2 from water. DNA is not formed by going down the thermodynamic hill. It takes energy to make it. Furthermore, the placement of the base pairs is not random. The first question to ask yourself is, "Why does this process which requires energy take place?" It goes against the laws of physic, both thermodynamics and entropy. The next issues is that of purpose. The base pairs of DNA do make up a code. They make a three letter alphabet which spells out "words" which translate into amino acids. DNA is the code for protiens and the code for assembling them in the proper order to create a new cell. DNA has a purpose which takes it out of the realm of chemistry. Non-living molecules do not have a purpose. They very nicely obey the laws of thermodynamics and entropy. The second question to ask is, "Why should small organic molecules assemble themselves into long strings in a very well defined fashion?" It's the difference between strings or random letters and words. Polymers do exist, but they are long strings of one small molecule- a monomer, or two alternating small molecules. Look up Nylon 66 for an example. DNA is unique in that it is non-random and has a purpose (recording information about protiens). Classical chemistry and physic don't explain why. So some people look further afield. If you can answer the two questions I posed, then you need not look further. If you can't, you and I can talk some more.

Answer 3

1 and 5

B is an exception to the octet rule. It is "satisfied" in the BF3 molecule with only six valence electrons.

However, because it 'could' accept 2 more electrons, it is very reactive.