Worksheet for identifying and grouping molecules by functional groups.

Let's solve Activity 1: SPOT THAT ELEMENT/S by grouping the molecules based on their functional groups — that is, the specific atoms or groups of atoms responsible for characteristic chemical reactions. We’ll identify the functional group in each molecule and then group them accordingly.

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🔍 Step-by-step Analysis

We will go through each molecule (A to U) and determine its functional group.

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#### ✔ Functional Group Identification:

| Letter | Structure | Functional Group | Name |
|--------|----------|------------------|------|
| A | CH₃–O–CH₃ | Ether | Dimethyl ether |
| B | CH₃–CH₂–OH | Alcohol | Ethanol |
| C | CH₃–CH₂–CH₂–O–H? Wait, this looks like CH₃–CH₂–CH₂–O–H → but it’s actually a primary alcohol with 3 carbons? Wait, let's look carefully. Actually, structure C shows: H₃C–CH₂–CH₂–O–H? No — wait, it's written as:
```
H H H
| | |
H-C-C-C-O-H
| | | |
H H H H
```
That’s propan-1-ol, so yes, alcohol. | Alcohol |
| D | H–C=O (formaldehyde) | Aldehyde | Formaldehyde |
| E | CH₃–O–CH₂–CH₃? Wait:
```
H H H H
| | | |
H-C-O-C-C-H
| | | |
H H H H
```
This is ethoxyethane? No: It's CH₃–O–CH₂–CH₃ → ethyl methyl ether → ether | Ether |
| F | CH₃–CH₂–CH₂–CH₂–OH → Butyl alcohol → alcohol | Alcohol |
| G | CH₃–CH₂–O–CH₂–CH₃ → Diethyl ether → ether | Ether |
| H | CH₃–CHO → Acetaldehyde → aldehyde | Aldehyde |
| I | CH₃–CO–CH₃ → Acetone → ketone | Ketone |
| J | CH₃–CH₂–NH₂ → Ethylamine → amine | Amine |
| K | CH₃–CH=CH₂ → Propene → alkene | Alkene |
| L | H–C(=O)–NH₂ → Formamide → amide | Amide |
| M | H–C(=O)–OH → Formic acid → carboxylic acid | Carboxylic acid |
| N | CH₃–CH₂–COOH → Propanoic acid → carboxylic acid | Carboxylic acid |
| O | CH₃–CO–O–CH₃ → Methyl acetate → ester | Ester |
| P | CH₃–CH₂–COO–CH₂–CH₃ → Ethyl propanoate → ester | Ester |
| Q | CH₃–CO–O–CH₂–CH₃ → Ethyl acetate → ester | Ester |
| R | CH₃–C(=O)–NH₂ → Acetamide → amide | Amide |
| S | CH₃–NH₂ → Methylamine → amine | Amine |
| T | H–C(=O)–OH → Formic acid → same as M → carboxylic acid | Carboxylic acid |
| U | CH₃–CH₂–C(=O)–H → Propanal → aldehyde | Aldehyde |

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🧩 Now, Grouping by Functional Groups

Let’s organize them into categories based on functional group.

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🟦 Group 1: Alcohols

- Contain –OH group attached to carbon.
- B, C, F

> B: CH₃CH₂OH → ethanol
> C: CH₃CH₂CH₂OH → 1-propanol
> F: CH₃(CH₂)₃OH → 1-butanol

✔ All have –OH bonded to an alkyl chain → alcohol

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🟨 Group 2: Ethers

- Contain –O– between two alkyl groups (R–O–R')
- A, E, G

> A: CH₃OCH₃ → dimethyl ether
> E: CH₃OCH₂CH₃ → ethyl methyl ether
> G: CH₃CH₂OCH₂CH₃ → diethyl ether

✔ All have oxygen bonded to two carbon atoms → ether

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🟩 Group 3: Aldehydes

- Contain –CHO group (C=O at terminal carbon)
- D, H, U

> D: HCHO → formaldehyde
> H: CH₃CHO → acetaldehyde
> U: CH₃CH₂CHO → propanal

✔ All have carbonyl (C=O) at the end of the chain → aldehyde

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🟪 Group 4: Ketones

- Contain C=O in the middle of the chain (not terminal)
- I

> I: CH₃COCH₃ → acetone

✔ Only one ketone here.

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🟫 Group 5: Amines

- Contain nitrogen bonded to carbon/hydrogen (–NH₂ or –N<)
- J, S

> J: CH₃CH₂NH₂ → ethylamine
> S: CH₃NH₂ → methylamine

✔ Both are primary amines → amine

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🟬 Group 6: Alkenes

- Contain C=C double bond
- K

> K: CH₃CH=CH₂ → propene

✔ Only one alkene.

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🟭 Group 7: Amides

- Contain –CONH₂ or similar (C=O bonded to nitrogen)
- L, R

> L: H–C(=O)–NH₂ → formamide
> R: CH₃–C(=O)–NH₂ → acetamide

✔ Both have carbonyl bonded to nitrogen → amide

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🟮 Group 8: Carboxylic Acids

- Contain –COOH group
- M, N, T

> M: HCOOH → formic acid
> N: CH₃CH₂COOH → propanoic acid
> T: HCOOH → same as M → formic acid

✔ All have –COOH group → carboxylic acid

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🟯 Group 9: Esters

- Contain –COOR group (carbonyl + OR)
- O, P, Q

> O: CH₃COOCH₃ → methyl acetate
> P: CH₃CH₂COOCH₂CH₃ → ethyl propanoate
> Q: CH₃COOCH₂CH₃ → ethyl acetate

✔ All have –COO– linkage → ester

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✔ Final Table: Grouped by Functional Group

| Functional Group | Letters | Reason |
|------------------|--------|-------|
| Alcohols | B, C, F | All have –OH group attached to carbon |
| Ethers | A, E, G | All have oxygen atom bonded to two alkyl groups |
| Aldehydes | D, H, U | All have carbonyl (C=O) at terminal carbon |
| Ketones | I | Carbonyl group in the middle of the chain |
| Amines | J, S | Nitrogen atom bonded to hydrogens and carbon |
| Alkenes | K | Contains carbon-carbon double bond |
| Amides | L, R | Carbonyl group bonded to nitrogen |
| Carboxylic Acids | M, N, T | All have –COOH group |
| Esters | O, P, Q | Carbonyl group bonded to oxygen and alkyl group (RCOOR') |

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💡 Summary of Categories:

- Alcohols: B, C, F
- Ethers: A, E, G
- Aldehydes: D, H, U
- Ketones: I
- Amines: J, S
- Alkenes: K
- Amides: L, R
- Carboxylic Acids: M, N, T
- Esters: O, P, Q

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✔ Final Answer (as per directions):

You are to write only the letters in the table under each category.

So, if you were to fill out the table:

| Category | Molecules |
|------------------------|----------|
| Alcohols | B, C, F |
| Ethers | A, E, G |
| Aldehydes | D, H, U |
| Ketones | I |
| Amines | J, S |
| Alkenes | K |
| Amides | L, R |
| Carboxylic Acids | M, N, T |
| Esters | O, P, Q |

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🎉 Conclusion:

You’ve successfully grouped the molecules by functional groups — the key feature that determines their chemical behavior. This activity helps in understanding how molecular structure dictates function in organic chemistry.

Let me know if you'd like this in a printable table format!