Draw the Lewis dot structure for water.
The Correct Answer and Explanation is:
The Lewis dot structure for water (H₂O) shows how the valence electrons are arranged around the atoms. Here’s the step-by-step process to draw it:
- Determine the total number of valence electrons:
- Oxygen (O) is in Group 16 of the periodic table, so it has 6 valence electrons.
- Hydrogen (H) is in Group 1, so each hydrogen atom has 1 valence electron.
- The total number of valence electrons is:
6 (from O)+2 (from 2 H’s)=8 valence electrons.6 \, \text{(from O)} + 2 \, \text{(from 2 H’s)} = 8 \, \text{valence electrons.}6(from O)+2(from 2 H’s)=8valence electrons.
- Arrange the atoms:
- Oxygen will be the central atom because it is more electronegative than hydrogen.
- Hydrogen atoms will be bonded to the oxygen atom.
- Distribute the electrons:
- Oxygen needs 2 electrons to form a bond with each hydrogen atom. Thus, each H atom shares 1 electron with oxygen.
- These shared pairs of electrons form single bonds (represented by a line between H and O).
- Now, oxygen has used 2 electrons (1 per bond) for bonding. Therefore, it has 4 remaining valence electrons.
- Place the remaining electrons around the oxygen atom:
- Oxygen will use its remaining 4 electrons to form lone pairs. Two lone pairs of electrons are placed on oxygen.
- Check the octet rule:
- Oxygen has 2 shared electrons from the hydrogen atoms and 4 lone electrons, so it has a total of 8 valence electrons, satisfying the octet rule.
- Each hydrogen atom has 2 electrons from the bond, satisfying the duet rule (for hydrogen, 2 electrons are enough to complete its valence shell).
Lewis Structure of Water (H₂O):
markdownCopyEdit H - O - H
..
- The dashes represent the shared pairs of electrons between oxygen and hydrogen (single bonds).
- The two dots above the oxygen atom represent lone pairs of electrons that are not involved in bonding.
Explanation:
Water’s Lewis structure shows that the oxygen atom shares electrons with two hydrogen atoms, forming two single bonds. This results in oxygen having two lone pairs and two bonds, giving it a full valence shell. Each hydrogen atom has one bond pair of electrons, fulfilling the duet rule. The structure is bent due to the repulsion between the lone pairs, and the bond angle is approximately 104.5°.
