What is the difference between primary, secondary and tertiary amine?

Counts alkyl groups on N: primary (one), secondary (two), tertiary (three). A fourth alkyl gives a quaternary ammonium salt. Note this classification is by substitution on N, not on the C attached to N.

What does N- mean in a name like N-methylethanamide?

N is a locant marking substitution on the nitrogen atom of the amide (or amine), not on a chain carbon. N,N-dimethyl means two methyls on N. Essential to avoid ambiguity.

Why do carboxylic acids beat ketones and alcohols in priority?

The order reflects oxidation state and chemical importance: carboxylic acid is the most oxidised state of C short of CO2 and participates in the widest range of reactions.

Nomenclature of Functional Groups

Q: What is a functional group in one sentence?

A specific atom or set of atoms attached to a hydrocarbon skeleton that determines the chemical family of the compound and how it reacts. Examples: -OH, -CHO, -COOH, -NH2.

Q: Why is -CHO always at C1 in an aldehyde name?

The aldehyde carbon is at the end of the chain by definition, so numbering starts there and its locant is always 1. No explicit number is written before -al.

Q: What is the difference between an aldehyde and a ketone?

Both have C=O, but aldehyde carbonyl carbon has at least one H and sits at chain end (suffix -al). Ketone carbonyl carbon has two other Cs and sits inside the chain (suffix -one).

Q: How do I name an ether?

As alkoxy alkane. Larger alkyl side becomes the parent; smaller side plus the oxygen becomes the alkoxy prefix. Example: CH3OCH(CH3)2 is 2-methoxypropane.

Q: What is an acyl group?

The R-CO- fragment left after removing -OH from a carboxylic acid. Naming: change -ic acid of the parent acid to -yl. Acetic to acetyl, ethanoic to ethanoyl.

Q: How do I decide the principal functional group when several are present?

Use IUPAC seniority: carboxylic acid > anhydride > ester > acid halide > amide > nitrile > aldehyde > ketone > alcohol > amine. Halide, nitro and alkoxy are always prefixes.

ChemistrySome Basic Principles of Organic ChemistryFor JEE aspirants

A functional group is the reactive atom or group of atoms in an organic compound that decides its chemistry and its name. Replacing an H in an alkane $R - H$ with a group G gives $R - G$ : R stays a hydrocarbon skeleton, but G controls the family the compound belongs to. Each family, from alkyl halides through alcohols, aldehydes, ketones, acids and their derivatives, amines and nitriles, has its own IUPAC secondary suffix. When more than one functional group is present in the same molecule, an IUPAC priority order decides which becomes the principal group (suffix) and which becomes a substituent (prefix).

Key Suffixes and Prefixes — Quick Reference

Alkyl halide: prefix halo- (fluoro, chloro, bromo, iodo). No suffix.
Alcohol ( $-$ OH): suffix -ol; prefix hydroxy-.
Ether (R $-$ O $-$ R'): named as alkoxy alkane; smaller alkyl is the alkoxy prefix.
Aldehyde ( $-$ CHO): suffix -al; prefix formyl- or oxo-.
Ketone ( $>$ C=O): suffix -one; prefix oxo-.
Carboxylic acid ( $-$ COOH): suffix -oic acid; prefix carboxy-.
Ester ( $-$ COOR'): alkyl alkanoate.
Acid halide ( $-$ COX): alkanoyl halide.
Amide ( $-$ CONH $_{2}$ ): alkanamide.
Amine ( $-$ NH $_{2}$ ): suffix -amine; prefix amino-.
Nitrile ( $-$ C $\equiv$ N): suffix -nitrile; prefix cyano-.
Nitro ( $-$ NO $_{2}$ ): prefix nitro-. No suffix.

1. The Idea of a Functional Group

A functional group is what makes a compound react a particular way. Formally, replace one hydrogen of an alkane skeleton with a group G:

R - H - H, + G R - G

where R is an alkyl skeleton

C_{n} H_{2n + 1}

and G is the functional group.

Every family below is built by picking a specific G, then following the naming template of the family. The parent chain is always the longest continuous chain that contains the principal functional group; the suffix of the family renames the parent from $-$ ane / $-$ ene / $-$ yne to its family suffix.

Figure 1: The same alkyl skeleton R gives rise to eight major families of organic compounds, one for each principal functional group G attached to it.

2. Alkyl Halides

General formula: $C_{n} H_{2n + 1} X$ or $R - X$ , where X is F, Cl, Br or I. The halogen is a substituent: it is always named as a prefix (fluoro, chloro, bromo, iodo) and never takes a suffix.

Pick the longest chain that contains the C bearing the halogen.
Number the chain from the end closer to the halogen (to give the halogen the lowest locant).
Prefix with locant + halogen name + parent alkane.

Solved Example 1

Name

C H_{3} - C H_{2} - CHBr - C H_{3}

Figure 2: 2-bromobutane. Br gets locant 2 because numbering starts from the closer end of the chain.

Solution

Four carbon chain, Br on C2 (numbering from the closer end). Assembled name: 2-bromobutane.

3. Alcohols

General formula: $C_{n} H_{2n + 1} OH$ . The IUPAC family name is alkanol. Rules:

Pick the longest continuous chain that contains the C bearing $-$ OH.
Number from the end nearer $-$ OH so it gets the lowest locant.
Number the positions of other substituents and list them as prefixes.
Change $-$ ane to $-$ ol (drop-e rule: the $e$ of the alkane drops before the vowel $o$ ).

3.1 Classification: 1°, 2° and 3° alcohols

Alcohols are classified by the carbon that carries the $-$ OH group. If that carbon is a 1° carbon, the alcohol is a primary alcohol. Similarly for 2° (secondary) and 3° (tertiary) alcohols.

Figure 3: Primary (1-propanol), secondary (2-propanol) and tertiary (2-methylpropan-2-ol) alcohols, classified by the carbon bearing

- OH

(highlighted).

Similar common names, different classifications. Isopropyl alcohol is a secondary alcohol, but isobutyl alcohol is a primary alcohol. Common names like "isopropyl" and "isobutyl" describe the alkyl group shape, not where the

-

OH sits.

3.2 Polyhydric alcohols (glycols)

Compounds with two $-$ OH groups are called glycols. Both hydroxyls are indicated with locants and the suffix becomes $-$ diol. Examples: ethane-1,2-diol (ethylene glycol, $HOC H_{2} C H_{2} OH$ ) and propane-1,2,3-triol (glycerol, $HOC H_{2} CH (OH) C H_{2} OH$ ).

Figure 4: Ethylene glycol (a diol) and glycerol (a triol). Locants are needed for each

- OH

group.

Rule (not a rule, actually a fact): Two or three

-

OH groups cannot sit on the same carbon: such a "gem-diol" or "gem-triol" is unstable and collapses to an aldehyde/ketone or carboxylic acid respectively.

Solved Example 2

Name

C H_{3} - CH (OH) - C H_{2} - C H_{3}

Solution

Four carbon chain, $-$ OH on C2 (numbering from the closer end). Parent: butane $\to$ butan-2-ol. Assembled: butan-2-ol. This is a 2° alcohol.

4. Ethers

Ethers are compounds where two carbon atoms bond to the same oxygen: $R - O - R^{'}$ . IUPAC names them as alkoxy alkane. Rules:

Identify the larger alkyl side: it becomes the parent alkane.
The smaller side (including the oxygen) becomes the alkoxy prefix: $- OC H_{3}$ = methoxy, $- O C_{2} H_{5}$ = ethoxy, and so on.
Number the parent chain so the alkoxy group gets the lowest locant.

Solved Example 3

Name

C H_{3} - O - CH (C H_{3})_{2}

Solution

Larger alkyl: propyl (from the isopropyl side). Smaller side with oxygen: methoxy. So parent is propane; the methoxy sits on C2 (the isopropyl branching carbon). Assembled: 2-methoxypropane.

5. Aldehydes

General formula: $R - CHO$ . The $-$ CHO carbon must be at the end of the parent chain, and it is always numbered C1. Family name: alkanal.

Longest chain includes the $-$ CHO carbon.
Change $-$ ane to $-$ al (drop the $e$ ).
No locant is needed for the $-$ CHO itself; it is always at C1.
Two $-$ CHO groups on the same chain (one at each end) $\to$ suffix -dial.
When $-$ CHO is attached to a ring, use $-$ carbaldehyde: cyclohexane $-$ carbaldehyde has the CHO hanging off the ring.

Figure 5: Aldehyde (ethanal,

C H_{3} CHO

) has

- CHO

at the chain end. Ketone (propan-2-one,

C H_{3} COC H_{3}

) has

> C = O

inside the chain.

Solved Example 4

Name

C H_{3} - C H_{2} - C H_{2} - CHO

Solution

Four carbon chain including the $-$ CHO C (which is C1). Parent: butane $\to$ butanal.

6. Ketones

General structure: $R - CO - R^{'}$ . The carbonyl carbon sits inside the chain (not at an end). Family name: alkanone.

Longest chain includes the C=O carbon.
Number from the end that gives the C=O the lowest locant.
Change $-$ ane to $-$ one and add the locant just before $-$ one.
Common naming: name the two alkyl groups on either side of C=O and add "ketone", e.g. methyl ethyl ketone for butan-2-one.

Solved Example 5

Name

C H_{3} - CO - C H_{2} - C H_{3}

Solution

Four carbon chain, C=O between C2 and C3. Numbering from the end that gives C=O the lower locant: C2. Assembled: butan-2-one. Common name: methyl ethyl ketone.

7. Carboxylic Acids

General formula: $R - COOH$ . Family name: alkanoic acid. The $-$ COOH carbon is at the end of the chain and is always C1.

Longest chain includes the $-$ COOH carbon.
Change $-$ ane to $-$ oic acid (drop-e).
No locant for $-$ COOH; it is C1.
Two $-$ COOH groups on the same chain $\to$ suffix -dioic acid (e.g. hexanedioic acid).
When $-$ COOH is attached to a ring, use $-$ carboxylic acid: cyclohexane $-$ carboxylic acid.

Figure 6: A monocarboxylic acid (ethanoic acid) and a dicarboxylic acid (ethanedioic acid, oxalic acid). Two

-

COOH groups on the parent chain change the suffix to

-

dioic acid.

Solved Example 6

Give the IUPAC name of citric acid,

HOOC - C H_{2} - C (OH) (COOH) - C H_{2} - COOH

Solution

Central three-carbon chain propane, with three $-$ COOH groups attached (one at each end and one on the central C) and one $-$ OH on the central C. Naming as a tricarboxylic acid with numbered $-$ COOH groups: 2-hydroxypropane-1,2,3-tricarboxylic acid.

8. Carboxylic Acid Derivatives (the Acyl Family)

Removing the $-$ OH from a carboxylic acid leaves an acyl group, $R - CO -$ . The acyl name is formed by changing the $-$ ic acid ending of the parent acid to $-$ yl: acetyl (from acetic), ethanoyl (from ethanoic), etc. Different X groups attached to the acyl C give a whole family of derivatives.

Figure 7: Carboxylic acid derivatives all share the

R - CO -

acyl core. Swapping X on the acyl carbon changes the family.

Figure 8: Four common derivatives of ethanoic acid obtained by replacing the –OH group of the carboxyl group

8.1 Acid Halides ( $-$ COX)

IUPAC name: alkanoyl halide. Change $-$ oic acid to $-$ oyl and add the halide as a separate word.

Example: $C H_{3} - COCl$ is ethanoyl chloride (common: acetyl chloride).

8.2 Acid Anhydrides

Two acyl groups sharing one oxygen: $R - CO - O - CO - R^{'}$ . IUPAC name: alkanoic anhydride. Replace "acid" with "anhydride" in the parent acid name.

Example: $(C H_{3} CO)_{2} O$ is ethanoic anhydride. When the two acyl groups are different, name both: butanoic ethanoic anhydride.

8.3 Esters ( $-$ COOR')

General formula: $R - COO R^{'}$ . IUPAC name: alkyl alkanoate.

The alkyl name (from R') comes first as a separate word.
The acid part becomes $-$ oate (drop the " $-$ ic acid" ending).

Example: $C H_{3} - COO - C_{2} H_{5}$ is ethyl ethanoate (common: ethyl acetate).

8.4 Amides ( $-$ CONH $_{2}$ )

IUPAC name: alkanamide. Change $-$ oic acid to $-$ amide (drop "acid").

Example: $C H_{3} - CON H_{2}$ is ethanamide.
N-alkyl substitution: if the N carries alkyl groups, prefix the substituent with capital $N$ : N-methylethanamide, N,N-diethylethanamide.
Aromatic N substitution (a phenyl on N): change $-$ amide to $-$ anilide. So $C H_{3} CO - NH - C_{6} H_{5}$ is ethananilide (also acetanilide).

8.5 Imides

Some dicarboxylic acids form cyclic amides where both acyl groups bond to the same nitrogen. The suffix -imide is used. Example: succinimide from succinic acid (butanedioic acid) $\to$ butanimide.

9. Amines

General formula: $R - N H_{2}$ (primary). IUPAC name: alkanamine or the group appears as an amino- prefix in more complex compounds.

9.1 Classification: 1°, 2°, 3°, quaternary

Amines are classified by the number of alkyl groups on the nitrogen, i.e. how many hydrogens of $N H_{3}$ have been replaced by an alkyl group.

Figure 9: Primary, secondary, tertiary amines and a quaternary ammonium salt, formed by progressive substitution of the H atoms of

N H_{3}

9.2 Simple amines

Name the alkyl group(s) on nitrogen, then add "amine": $C H_{3} N H_{2}$ is methylamine; $(C H_{3})_{2} NH$ is dimethylamine. More complex amines use $-$ amine as a suffix on the parent chain, with the amino carbon getting the lowest locant: pentan-2-amine, for example.

9.3 Aromatic amines

Aromatic amines have the nitrogen attached directly to a benzene ring. They are usually named as derivatives of the parent aniline ( $C_{6} H_{5} N H_{2}$ ). Example: 2-chloroaniline, 4-methylaniline.

Figure 10: Aniline (parent aromatic amine) and a substituted example, 4-methylaniline. Ring positions are numbered with

- N H_{2}

carbon as C1.

9.4 Amine salts and quaternary ammonium salts

Replace $-$ amine with $-$ ammonium (or $-$ aniline with $-$ anilinium) and add the anion name: methylammonium chloride, tetramethylammonium bromide.

10. Nitro and Related Compounds

General formula (nitroalkane): $C_{n} H_{2n + 1} N O_{2}$ . The $-$ NO $_{2}$ group is always a substituent prefix: nitro-. Family: nitroalkane.

Solved Example 7

Name

C H_{3} - CH (N O_{2}) - C H_{3}

Solution

Three carbon chain, $-$ NO $_{2}$ on C2. Assembled name: 2-nitropropane.

10.1 Alkyl nitrites

These are the isomers of nitroalkanes with the oxygen inside: $R - O - N = O$ . Common name only: alkyl nitrite. IUPAC does not assign a systematic name to this arrangement. Example: $C H_{3} C H_{2} - ONO$ is ethyl nitrite.

Figure 11: Nitroethane and ethyl nitrite are constitutional isomers. Nitro has C

-

N; nitrite has C

-

-

11. Alkyl Cyanides (Nitriles) and Isocyanides

11.1 Nitriles ( $-$ C $\equiv$ N)

General formula: $R - C \equiv N$ . IUPAC name: alkanenitrile. The nitrile carbon is counted in the chain and becomes C1.

Example: $C H_{3} - C \equiv N$ is ethanenitrile (common name: acetonitrile). $C H_{3} - CH (C H_{3}) - C \equiv N$ is 2-methylpropanenitrile.

11.2 Isocyanides ( $-$ NC)

General formula: $R - N \equiv C$ . Only common names are used: alkyl isocyanide or alkyl isonitrile. Example: $C H_{3} - NC$ is methyl isocyanide (also methyl isonitrile). There is no specific IUPAC systematic name.

Figure 12: Acetonitrile (

C H_{3} - C \equiv N

) and methyl isocyanide (

C H_{3} - N \equiv C

) are constitutional isomers — same formula, different atom that bonds to the alkyl.

12. Multi-Functional Compounds and Priority Order

When a molecule contains more than one functional group, IUPAC uses a fixed seniority list. The highest-priority group is treated as the principal functional group (secondary suffix in the name); every other group becomes a prefix.

Figure 13: IUPAC priority pyramid. The highest-ranked group in the molecule becomes the suffix; every other group becomes a prefix.

Rank	Class	As suffix	As prefix
1 (highest)	Carboxylic acid	-oic acid	carboxy-
2	Acid anhydride	-oic anhydride	—
3	Ester	alkyl -oate	alkoxycarbonyl-
4	Acid halide	-oyl halide	haloalkanoyl-
5	Amide	-amide	carbamoyl-
6	Nitrile	-nitrile	cyano-
7	Aldehyde	-al	formyl- / oxo-
8	Ketone	-one	oxo-
9	Alcohol	-ol	hydroxy-
10	Amine	-amine	amino-
11	Multiple bonds	-ene / -yne	—
12 (always prefix)	Halide, Nitro, Alkoxy	—	halo-, nitro-, alkoxy-

How to use the table. Find the highest-ranked group in your compound: that determines the family suffix. Every other group in the molecule is named as a prefix (using the "as prefix" column) and numbered off the chain-end that gave the principal group the lowest locant.

Figure 14: Naming

HOC H_{2} C H_{2} COOH

-

COOH wins priority: parent is propanoic acid;

-

OH becomes a 3-hydroxy prefix.

Solved Example 8

Name

HO - C H_{2} - C H_{2} - COOH

Solution

The compound has both $-$ OH and $-$ COOH. Priority: $-$ COOH beats $-$ OH. So $-$ COOH becomes the suffix ( $-$ oic acid) and $-$ OH becomes a prefix (hydroxy-). Longest chain: 3 carbons including $-$ COOH (C1). $-$ OH sits on C3. Assembled name: 3-hydroxypropanoic acid. See Figure 14 above for the priority breakdown.

Solved Example 9

Name

C H_{3} - CO - C H_{2} - C H_{2} - OH

Solution

Ketone ( $>$ C=O) vs alcohol ( $-$ OH): ketone wins. Suffix: $-$ one. $-$ OH becomes a prefix (hydroxy-). Longest chain: 4 carbons. Number from the C=O end so it gets the lowest locant: C1 = CH $_{3}$ , C2 = C=O, C3 = CH $_{2}$ , C4 = CH $_{2}$ OH. Assembled: 4-hydroxybutan-2-one.

Common Mistakes to Avoid

Watch out

Treating the aldehyde or acid carbon as a substituent. The $-$ CHO and $-$ COOH carbons are always included in the parent chain and always numbered as C1. Do not leave them out of the count.
Using $-$ one for an aldehyde or $-$ al for a ketone. $-$ al ends the aldehyde (terminal), $-$ one names the ketone (internal). The difference is whether the carbonyl C has an H on it (aldehyde) or two carbons (ketone).
Wrong parent choice in an ether. The larger alkyl side is the parent; the smaller side is the alkoxy prefix. Reversing them gives an incorrect name.
Mixing up "isopropyl" and "sec-butyl" classifications. The name describes the alkyl skeleton; it does not tell you whether an $-$ OH on that group is primary, secondary or tertiary. Look at the C bearing the group.
Using acetic acid vs ethanoic acid inconsistently in the same name. Common names and IUPAC names should not be mixed within a single compound name.
Wrong priority ranking. Carboxylic acids outrank ester, ester outranks amide, amide outranks nitrile, nitrile outranks aldehyde, aldehyde outranks ketone, ketone outranks alcohol, alcohol outranks amine. Halide, nitro and alkoxy are always prefixes.
Skipping N locant for substituted amides / amines. If an alkyl group is on the nitrogen, you must use the capital italic $N$ locant (e.g. N-methyl). Missing this is a common mistake.

Frequently Asked Questions

Q1. What is a functional group in one sentence?

A functional group is the specific atom or set of atoms attached to the hydrocarbon skeleton that determines both the chemical family of the compound and how it reacts. Common examples are $-$ OH (alcohol), $-$ CHO (aldehyde), $-$ COOH (carboxylic acid) and $-$ NH $_{2}$ (amine).

Q2. Why is $-$ CHO always at C1 in an aldehyde name?

Because the aldehyde carbon is by definition at the end of the chain (it carries a hydrogen). Since it is a chain terminus, numbering starts there and the locant is always 1, so no explicit number is written before " $-$ al".

Q3. What is the difference between an aldehyde and a ketone?

Both contain the carbonyl group C=O, but in an aldehyde the carbonyl carbon has at least one hydrogen and sits at the end of the chain (suffix $-$ al). In a ketone the carbonyl carbon has two other carbons attached and sits inside the chain (suffix $-$ one).

Q4. How do I name an ether?

Ethers are named as alkoxy alkanes. The larger alkyl side is the parent (alkane); the smaller side plus the oxygen becomes the alkoxy prefix. $C H_{3} O C_{2} H_{5}$ is methoxyethane; $C H_{3} OCH (C H_{3})_{2}$ is 2-methoxypropane.

Q5. What is an acyl group?

An acyl group is what remains after you remove the $-$ OH from a carboxylic acid: $R - CO -$ . The whole family of carboxylic acid derivatives (acid halides, anhydrides, esters, amides) is built by attaching different groups to the acyl carbon. Naming: change the $-$ ic acid of the parent acid to $-$ yl (acetic $\to$ acetyl, ethanoic $\to$ ethanoyl).

Q6. How do I decide which functional group is the principal group when more than one is present?

Use the IUPAC seniority ranking. From highest to lowest: carboxylic acid, acid anhydride, ester, acid halide, amide, nitrile, aldehyde, ketone, alcohol, amine. The highest-ranking group becomes the secondary suffix; the rest become prefixes. Halide, nitro and alkoxy are always named as prefixes.

Q7. What is the difference between a primary, secondary and tertiary amine?

The classification counts how many alkyl groups are attached to nitrogen: primary (one), secondary (two), tertiary (three). Adding a fourth alkyl group gives a quaternary ammonium salt with a positive charge on N and a counter-anion. Note this is different from alcohols, where the classification is based on the carbon bearing $-$ OH, not on the substitution around O.

Q8. What does the "N" prefix mean in a name like N-methylethanamide?

The italic capital $N$ is a locant that tells you the methyl substituent is attached to the nitrogen atom of the amide (not to a carbon of the chain). Similarly N,N-dimethyl means two methyl groups on N; N-ethyl-N-methyl means one of each. This convention is essential for amides and amines because otherwise the position of the alkyl group would be ambiguous.

Q9. Why do carboxylic acids beat ketones and alcohols in the priority order?

The priority order reflects the oxidation state and chemical importance of the group. Carboxylic acids are the most oxidised state of carbon short of $C O_{2}$ , and they participate in the widest range of reactions (salt formation, ester and amide chemistry, decarboxylation). The order also matches the order in which these groups are historically classified in organic chemistry textbooks.

Previous year questions on Nomenclature of Functional Groups

1 question from past papers, each with a step-by-step solution.

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1. The Idea of a Functional Group

2. Alkyl Halides

3. Alcohols

3.1 Classification: 1°, 2° and 3° alcohols

3.2 Polyhydric alcohols (glycols)

4. Ethers

5. Aldehydes

6. Ketones

7. Carboxylic Acids

8. Carboxylic Acid Derivatives (the Acyl Family)

8.1 Acid Halides (−COX)

8.2 Acid Anhydrides

8.3 Esters (−COOR')

8.4 Amides (−CONH2​)

8.5 Imides

9. Amines

9.1 Classification: 1°, 2°, 3°, quaternary

9.2 Simple amines

9.3 Aromatic amines

9.4 Amine salts and quaternary ammonium salts

10. Nitro and Related Compounds

10.1 Alkyl nitrites

11. Alkyl Cyanides (Nitriles) and Isocyanides

11.1 Nitriles (−C≡N)

11.2 Isocyanides (−NC)

12. Multi-Functional Compounds and Priority Order

Common Mistakes to Avoid

Frequently Asked Questions

Q1. What is a functional group in one sentence?

Q2. Why is −CHO always at C1 in an aldehyde name?

Q3. What is the difference between an aldehyde and a ketone?

Q4. How do I name an ether?

Q5. What is an acyl group?

Q6. How do I decide which functional group is the principal group when more than one is present?

Q7. What is the difference between a primary, secondary and tertiary amine?

Q8. What does the "N" prefix mean in a name like N-methylethanamide?

Q9. Why do carboxylic acids beat ketones and alcohols in the priority order?

Previous year questions on Nomenclature of Functional Groups

Ready to master Some Basic Principles of Organic Chemistry?

8.1 Acid Halides ( $-$ COX)

8.3 Esters ( $-$ COOR')

8.4 Amides ( $-$ CONH $_{2}$ )

11.1 Nitriles ( $-$ C $\equiv$ N)

11.2 Isocyanides ( $-$ NC)

Q2. Why is $-$ CHO always at C1 in an aldehyde name?