# Review my work?

1. Apr 19, 2005

### RPN

Okay I did my work but if someone would be so kind as to look at it and see if I am understanding.
Questions
1. Explain why you would expect a BeF2 molecule to be linear but an SF2 molecule to be angular?
BeF2 forms an ionic bond with 2 single bonds. Since Be is in group IIA it forms two sp hybrid orbitals. The farthest away the pairs can be is 180 o angle, making it linear. SF2 forms two covalent bonds with two F atoms. Having four pairs of electrons around the S atom the farthest away they can be is in an angular shape.

2a) How would you designate the hybrid orbitals formed by "mixing" one d, one s and two p orbitals?
a) When mixing one d orbital, one s orbital and 2 p orbitals you get dsp2.
b) How many of the hybrid orbitals would be formed by the mixing?
b) The number you put in is the number you get as a result. So in this case we put in 4 orbitals we then get 4 hybrid orbitals.

3. Explain why C20H40 is a solid at 25degcel, while C4H8 is a gas at 25degcel?
39. C20H40 is a solid at 25o C because has more electrons. With more electrons you get more forces that can hold the lattice pattern together. C4H8 is a gas at 25o C because the bonds are weak and that gives this compound a low boiling temp.

4.Arrange the following atoms or ions in order of increasing radius:
Cl, S2-, K, K+, O
if an explanation for teh position of S2- in relation to the atom or ion in front and behind it.
OK I have:31.
O, S2-, K+, Cl ,K
------------------>

S2- is smaller than K+ in this case because it has a configuration the same as Ar, a noble gas. Moving horizontally in the periodic table the radius decreases in size.
S2- is bigger than Cl because?
If someone would look over my answers and see if i am correct or even close.
Thank you

2. Apr 19, 2005

### dextercioby

2 is entirely correct.1 is okay.Indeed the nonbonding pairs distort the linear structure.At 3,there's a connection between the molar mass and the the # of atoms in the hydro-carbide.

4.The order should be

O,Cl,K^{+},S^{2-},K

------------------------------>

1.The # of electrons and the # of shells are the main criteria.
2.For isoelectronic configurations,the largest radius corresponds to the smaller nuclear charge.

Daniel.

3. Jun 14, 2005

### J_o_S

oops.

Sorry about that, I should read better before posting.. I understand it now

Last edited: Jun 14, 2005