Question

explain the formation of the covalent bond in the co2

Answer 1

Answer:

Carbon is in group 4 of the periodic table. Two oxygen atoms and 1 carbon atom will each share two electrons to form four covalent bonds and make a carbon dioxide molecule(CO2).

Answer 2

The shapes of simple molecules containing double bonds

Carbon dioxide, CO2

Carbon dioxide could be drawn (without making any assumptions about the shape) as

The carbon originally had 4 electrons in its outer level (group 4). Each oxygen contributes 2 electrons - 1 for each bond. That means there are a total of 8 electrons around the carbon, in 4 pairs. Because there are 4 bonds, these are all bond pairs.

Each double bond uses 2 bond pairs - which are then thought of as a single unit. Those two double bond units will try to get as far apart as possible, and so the molecule is linear. The structure we've drawn above does in fact represent the shape of the molecule.

Sulphur dioxide, SO2

Sulphur dioxide could be drawn exactly the same as carbon dioxide (again without making any assumptions about the shape):

The argument develops differently though. Sulphur has 6 electrons in its outer level, and the oxygens between them contribute another 4 (1 for each bond). That gives 10 electrons in total - 5 pairs. 4 pairs are needed for the bonds, leaving 1 lone pair. Each double bond uses 2 bond pairs and can be thought of as a single unit.

There are 2 double bond units and 1 lone pair, which will try to get as far apart as possible - taking up a trigonal planar arrangement.

Because the lone pair isn't counted when you describe the shape, SO2 is described as bent or V-shaped. In this case, our original structure misrepresented the shape.

The shapes of ions containing double bonds

This is much more tricky. Before you can do anything else, you need to know exactly how the ion is bonded - which bonds are double, which bonds are single, and where