Free Printable Lewis Dot Structure Worksheets - Free Printable

Let's solve this Electron Dot Structure Worksheet step by step.

---

Part (1): Draw the electron dot structure for the following elements.

Electron dot structures (also called Lewis dot structures) show the valence electrons of an atom as dots around the element symbol.

We use the periodic table to determine the number of valence electrons:

| Element | Group | Valence Electrons | Electron Dot Structure |
|--------------|-------|-------------------|------------------------|
| Lithium (Li) | 1 | 1 | `Li•` |
| Calcium (Ca) | 2 | 2 | `Ca:` |
| Chlorine (Cl)| 17 | 7 | `:Cl:` (with 7 dots) |
| Germanium (Ge)| 14 | 4 | `:Ge:` (with 4 dots) |
| Beryllium (Be)| 2 | 2 | `Be:` |
| Xenon (Xe) | 18 | 8 | `:Xe:` (with 8 dots) |

> 💡 Note: Dots are placed on four sides (top, right, bottom, left), with no more than two dots per side.

#### ✔ Final Answers:
- Lithium (Li): `Li•`
- Calcium (Ca): `Ca:` (two dots)
- Chlorine (Cl):
```
..
:Cl:
..
```
(Seven dots: three pairs and one single dot — usually drawn as two lone pairs on top and bottom, one pair on right, and one unpaired on left or vice versa.)
- Germanium (Ge):
```
..
:Ge:
..
```
(Four dots, one on each side)
- Beryllium (Be): `Be:` (two dots)
- Xenon (Xe):
```
..
:Xe:
..
```
(Eight dots: four pairs)

---

Part (2): Draw the Lewis structure for the following hydrocarbons.

We’ll draw Lewis structures, showing all atoms and bonds (lines = shared pairs, dots = lone pairs).

---

#### 1. C₂H₅OH (Ethanol)

- Formula: CH₃–CH₂–OH
- Carbon has 4 bonds, O has 2 bonds, H has 1 bond.
- Oxygen in OH has two lone pairs.

```
H H
| |
H–C–C–O–H
| |
H H
```

But properly written with correct bonding:

```
H H
| |
H–C–C–O–H
| |
H H
```

Wait! The second carbon is bonded to O, so it should be:

```
H H
| |
H–C–C–O–H
| |
H H
```

But oxygen must have two lone pairs.

Final structure:

```
H H
| |
H–C–C–O–H
| |
H H
```

With two lone pairs on O.

✔ Correct Lewis structure:

```
H H
| |
H–C–C–O–H
| |
H H
```

And two lone pairs on the oxygen atom.

---

#### 2. C₂H₅Cl (Chloroethane)

- Cl replaces one H in ethane.
- Cl has 3 lone pairs.

Structure:

```
H H
| |
H–C–C–Cl
| |
H H
```

With three lone pairs on Cl.

---

#### 3. CH₃OCH₃ (Dimethyl ether)

- Central O bonded to two CH₃ groups.
- O has two lone pairs.

```
H H
| |
H–C–O–C–H
| |
H H
```

With two lone pairs on O.

---

#### 4. CH₃COOH (Acetic acid)

- Carboxylic acid group: –COOH
- One carbon double-bonded to O, single-bonded to OH and CH₃.
- Oxygen in OH has two lone pairs; double-bonded O has two lone pairs.

Structure:

```
H
|
H–C–C(=O)–O–H
|
H
```

More clearly:

```
H
|
H–C–C=O
| \
H O–H
|
(lone pairs on both O atoms)
```

Better:

```
H
|
H–C–C=O
| \
H O–H
|
(lone pairs on both O)
```

Double bond between C and O, single bond from C to O–H.

Oxygen in C=O has two lone pairs.
Oxygen in O–H has two lone pairs.

✔ Final:

```
H
|
H–C–C=O
| \
H O–H
|
(lone pairs on both O atoms)
```

---

#### 5. C₃H₈ (Propane)

- Three carbons in chain: CH₃–CH₂–CH₃

```
H H H
| | |
H–C–C–C–H
| | |
H H H
```

Each carbon has 4 bonds.

✔ Correct.

---

#### 6. H₂CO (Formaldehyde)

- Carbon double-bonded to O, two H’s attached to C.

```
H
|
H–C=O
|
(no lone pairs on C)
```

Oxygen has two lone pairs.

```
H
|
H–C=O
|
(double bond)
```

With two lone pairs on O.

---

#### 7. C₂H₆ (Ethane)

- Two carbons single-bonded, each bonded to 3 H’s.

```
H H
| |
H–C–C–H
| |
H H
```

✔ Correct.

---

#### 8. C₂H₄ (Ethene)

- Double bond between two carbons.

```
H H
\ /
C=C
/ \
H H
```

Each carbon has 2 H’s and double bond.

✔ Correct.

---

#### 9. C₂H₂ (Ethyne)

- Triple bond between two carbons.

```
H–C≡C–H
```

Each carbon has one H and triple bond.

✔ Correct.

---

✔ Summary of Lewis Structures (Text Representation):

| Compound | Lewis Structure (Simplified Text) |
|----------------|-----------------------------------|
| C₂H₅OH | H₃C–CH₂–OH (O has 2 lone pairs) |
| C₂H₅Cl | H₃C–CH₂–Cl (Cl has 3 lone pairs) |
| CH₃OCH₃ | H₃C–O–CH₃ (O has 2 lone pairs) |
| CH₃COOH | H₃C–C(=O)–OH (both O have 2 lone pairs) |
| C₃H₈ | CH₃–CH₂–CH₃ |
| H₂CO | H₂C=O (O has 2 lone pairs) |
| C₂H₆ | CH₃–CH₃ |
| C₂H₄ | H₂C=CH₂ |
| C₂H₂ | HC≡CH |

---

🔍 How to Draw These Properly:

- Carbon: Always forms 4 bonds.
- Hydrogen: Forms 1 bond.
- Oxygen: Forms 2 bonds, has 2 lone pairs.
- Chlorine: Forms 1 bond, has 3 lone pairs.
- Double/triple bonds: Use lines accordingly.
- Lone pairs: Show as dots (usually omitted in skeletal, but required here).

---

✔ Final Answer Summary:

#### (1) Electron Dot Structures:
- Li: `Li•`
- Ca: `Ca:` (two dots)
- Cl: `:Cl:` (seven dots: three pairs + one unpaired)
- Ge: `:Ge:` (four dots)
- Be: `Be:` (two dots)
- Xe: `:Xe:` (eight dots: four pairs)

#### (2) Lewis Structures:
- C₂H₅OH: H₃C–CH₂–OH (O has two lone pairs)
- C₂H₅Cl: H₃C–CH₂–Cl (Cl has three lone pairs)
- CH₃OCH₃: H₃C–O–CH₃ (O has two lone pairs)
- CH₃COOH: H₃C–C(=O)–OH (both O have two lone pairs)
- C₃H₈: CH₃–CH₂–CH₃
- H₂CO: H₂C=O (O has two lone pairs)
- C₂H₆: CH₃–CH₃
- C₂H₄: H₂C=CH₂
- C₂H₂: HC≡CH

---

Let me know if you'd like a visual version (ASCII art) or diagrams for any specific molecule!