Grade 11 : Chemistry - Organic Chemistry Basics (Set 1)

Explanation: In methane ($CH_4$), carbon forms four single $\sigma$ bonds with four hydrogen atoms using four equivalent hybridized orbitals, resulting in $sp^3$ hybridization and a tetrahedral geometry.

Explanation: Acyclic (open-chain) alkanes are saturated hydrocarbons containing only single covalent bonds. Their general molecular formula is $C_n H_{2n+2}$, where $n$ is the number of carbon atoms.

Explanation: The chain consists of 2 carbon atoms (root word: eth-) with a hydroxyl functional group ($-OH$), giving the suffix '-ol'. Hence, the IUPAC name is Ethanol.

Explanation: Isomers are compounds having the exact same molecular formula but different structural arrangements of atoms, resulting in distinct physical and chemical properties.

Explanation: An $sp^3$ hybridized carbon atom forms a regular tetrahedral geometry with ideal bond angles of $109.5^\circ$ (or $109^\circ 28'$).

Explanation: Aldehydes contain the formyl functional group, represented as $-CHO$, attached at the end of a carbon chain.

Explanation: Adjacent members of any homologous series differ by a single methylene unit, $-CH_2-$, which corresponds to a molecular mass difference of 14 u.

Explanation: Each carbon in ethene forms three $\sigma$ bonds and one $\pi$ bond, resulting in $sp^2$ hybridization and a trigonal planar geometry around each carbon atom.

Explanation: In homolytic fission, the shared electron pair is divided equally between the two bonding atoms, producing neutral species with unpaired electrons known as free radicals.

Explanation: Carboxylic acids are characterized by the carboxyl functional group, $-COOH$, composed of a carbonyl group ($C=O$) attached to a hydroxyl group ($-OH$).

Explanation: The straight-chain alkane contains 4 carbon atoms connected by single bonds. According to IUPAC rules, the root word for 4 carbons is 'but-' and the suffix is '-ane', giving Butane.

Explanation: Catenation refers to the self-linking capability of carbon atoms through covalent bonds to form long continuous chains, branched structures, or rings.

Explanation: Electrophiles are electron-loving species (Lewis acids) that are electron-deficient and seek an electron pair to establish a bond.

Explanation: In heterolytic cleavage, the shared pair of electrons is retained entirely by one of the bonded atoms, yielding a carbocation (positive) and an anion (negative).

Explanation: The ketone molecule has 3 carbon atoms (root: prop-) and a carbonyl group at carbon 2. Thus, the IUPAC name is Propanone.

Explanation: In ethyne ($HC\equiv CH$), each carbon forms two $\sigma$ bonds and two $\pi$ bonds, leading to sp hybridization with a linear geometry ($180^\circ$).

Explanation: Standard IUPAC prefixes for carbon chain lengths are: 1 = meth-, 2 = eth-, 3 = prop-, 4 = but-. Thus, for 3 carbons, the prefix is Prop-.

Explanation: Both compounds have the same carbon chain skeleton and functional group ($-OH$), but differ in the position of the $-OH$ group (carbon 1 vs carbon 2). Therefore, they are position isomers.

Explanation: Nucleophiles (nucleus-seeking) are electron-rich species (Lewis bases) containing at least one unshared pair of electrons that can be donated to an electrophilic center.

Explanation: Alkenes containing one carbon-carbon double bond have two fewer hydrogen atoms than corresponding alkanes, giving the general formula $C_n H_{2n}$.