Question One
Let's start with what is not true. E is utter nonsense. Hydrogen for a halogen is a 1 to 1 trade. You give up Michael Jordan, you get Shaq. One for one.
A is not true. The halogen came from a single bond. The hydrogen merely takes it's place.
C is not right either. The bonds between the Carbon atoms don't change. What does is the polar charge that the halogen created. The halogen takes on an electron which makes the molecule minus on the halogen end and positive on the carbon chain.
B is not right. Because the polar charge has been removed, the boiling point will decrease. You have to read this rather carefully. Down and up are bad news in science and you will become better in the sciences when you know what down and up mean.
So we are left with D. D is the correct answer. You now have a very pure saturated compound (but it was before).
Question Two
Start with Sulfur's uncharge state. It has 16 electrons. Those 16 fill up in the following way
1s^2 2s^2 2p^6 3s^2
So far what we have used up 2 + 2 + 6 + 2 = 12
We need to fill up 4 more to put somewhere. That somewhere is in the 3p^6 orbital only we have only 4 more to go. There is a space for 2 more elections in th 3p level.
P level electrons can contain only 6 elections. So whatever follows will complete the 3p level. That's why sulfur's most common charge is - 2
When 2 more electrons are taken on two things are true.
1. The charge is - 2
2. The orbital that fills up is 3p and it becomes 3p^6