Carbon Bonding and Functional Groups Answers

Question

Carbon Bonding and Functional GroupsPart A — Carbon bondingFive displayed structures include: (1) a six-membered C/N ring with two carbonyls and one C=C bond; (2) a three-carbon alkene whose terminal carbon is drawn with only three bonds; (3) a three-carbon chain with an O substituent and terminal carbonyl; (4) a three-carbon alcohol chain; and (5) an amino-acid-like structure whose carbon between N and the carboxyl carbon has only three bonds. Select the three structures in which every carbon has the appropriate number of bonds.Part B — Identifying functional groupsA six-carbon molecule contains four functional groups. Select all atoms belonging to those groups, without selecting bonds. The reference set includes hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate structures.Part C — Classifying moleculesFor each bin—alcohol, aldehyde, carboxylic acid, amine, thiol, and organic phosphate—match one displayed molecule and the best property: polar and more water-soluble; possible structural isomer of a ketone; acts as an acid; acts as a base; forms disulfide bonds; or contributes negative charge.

Part A — Carbon bonding Select structures 1, 3, and 4. Count bond order around every carbon: a single bond counts as 1, a double bond as 2, and a triple bond as 3. A neutral carbon in these structures must total 4. Structure Carbon-bond check Result 1. Six-membered C/N ring with two C=O groups and one C=C Every carbon totals four bond orders Select 2. Three-carbon alkene as drawn The terminal carbon shows only three bond orders Do not select 3. Three-carbon chain with an O substituent and terminal C=O Every carbon totals four bond orders Select 4. Three-carbon alcohol chain Every carbon totals four bond orders Select 5. Amino-acid-like structure as drawn The carbon between N and the carboxyl carbon shows only three bond orders Do not select Part B — Functional groups in the molecule Highlight the atoms in these four groups attached to the six-carbon chain: hydroxyl: -OH sulfhydryl: -SH amino: -NH₂ phosphate: -OPO₃²⁻ Do not highlight the bonds or the ordinary carbon-and-hydrogen skeleton. Part C — Classifying by functional group Compound Functional group Formula Best-matching property Alcohol Hydroxyl -OH Polar and makes compounds more soluble in water Aldehyde Carbonyl C=O at the end of a skeleton May be a structural isomer of a ketone Carboxylic acid Carboxyl -COOH Acts as an acid Amine Amino -NH₂ Acts as a base Thiol Sulfhydryl -SH Forms disulfide bonds Organic phosphate Phosphate -OPO₃²⁻ Contributes negative charge The molecule and property must both go into the matching bin. Start from the diagnostic atoms, then use the chemical behavior as a check.

Structure	Carbon-bond check	Result
1. Six-membered C/N ring with two C=O groups and one C=C	Every carbon totals four bond orders	Select
2. Three-carbon alkene as drawn	The terminal carbon shows only three bond orders	Do not select
3. Three-carbon chain with an O substituent and terminal C=O	Every carbon totals four bond orders	Select
4. Three-carbon alcohol chain	Every carbon totals four bond orders	Select
5. Amino-acid-like structure as drawn	The carbon between N and the carboxyl carbon shows only three bond orders	Do not select

Compound	Functional group	Formula	Best-matching property
Alcohol	Hydroxyl	−OH	Polar and makes compounds more soluble in water
Aldehyde	Carbonyl	C=O at the end of a skeleton	May be a structural isomer of a ketone
Carboxylic acid	Carboxyl	−COOH	Acts as an acid
Amine	Amino	−NH₂	Acts as a base
Thiol	Sulfhydryl	−SH	Forms disulfide bonds
Organic phosphate	Phosphate	−OPO₃²⁻	Contributes negative charge

Evidence boundary

Part A numbers the structures from top to bottom in the publicly visible five-option screenshot. This text version replaces the original interactive drawings and highlighting with structure descriptions and a bond-order audit. If another course version rearranges the drawings, use the structure and carbon bond count rather than the option position.

Sources

These references support the concepts and methods used in the explanation above.