studying micro--help me with Hydrogen bond, please?

Question

Question is..Hydrogen bonds can form between___ adjacent to each other. (a.) two hydrogen atoms (b.) two Oxygen atoms, (c) a hydrogen and an Oxygen atom or (d) negative charges

Answer 1

The correct answer is c.

A hydrogen bond is NOT like an ionic or covalent bond. A single molecule of H2O will have NO hydrogen bonds, even though it has plenty of hydrogen. Those bonds are of the regular type with a fair amount of ionic character because oxygen is more electronegative that hydrogen.

It is that ionic character that gives a water molecule a net dipole moment which makes it a good solvent for polar molecules, and it is that ionic character which is also reponsible for water forming lots of hydrogen bonds as well.

When a BONDED hydrogen is attached to something that pulls the electrons largely away, it starts to resemble a naked proton. Though it doesn't necessarily do anything so overt as pick up a large charge, it will nonetheless be attracted to other atoms that have a tons of electrons lying around and a partial negative charge to boot.

As you can imagine, there are plenty of both kinds of atoms in a sample of water, and this is what is observed. It is estimated that each water molecule is hydrogen-bonded to at least two OTHER water molecules at all times. This is why water has such a comparatively high boiling point and it is also why ice has a larger volume than water (since the molecules can't move as much, they are frozen in more limited positions of maximal hydrogen bonding)!

Hydrogen bonds have MUCH lower energy than ionic/covalent ones, so in normal conditions they are constantly being broken and re-established. So although a water molecule is hydrogen-bonded to more than three others, a second later it is probably three entirely different ones.

Hope that helps!

Answer 2

It's C because remember, a hydrogen bond is a weak intermolecular attraction between a single bonded hydrogen and an adjacent electronegative element (can only be N, O, or F). A hydrogen bond wouldn't form between two hydrogen atoms because that interaction is called an induced dipole interaction. The same is with 2 oxygen atoms. So A and B can be eliminated. D can also be eliminated because the bonding resulting from charges is ionic bonding, not hydrogen bonding. Therefore, C is the only possible answer.

Answer 3

Hi. C would give you H2O. Just remember that hydrogen only has 1 electron and the shell "wants" 2. So it will share an electron with any element that has one or more to give.