Deck 2:Isomerism

Question 1

Structural isomers

Answer 1

Structural isomers are molecules with the same molecular formula but with different structural arrangements of atoms.

Question 2

Stereoisomers

Answer 2

Stereoisomers are compounds with the same structural formula, but with a different arrangement of atoms in space.

Question 3

E/Z isomerism

Answer 3

E/Z isomerism is a type of isomerism in which different groups attached to each carbon of a C=C double bond may be arranged differently in space because of the restricted rotation of the C=C bonds.

Question 4

cis-trans isomerism

Answer 4

cis-trans isomerism is a special type of E/Z isomerism in which there is a non-hydrogen group and hydrogen on each C of a C=C double bond: the cis isomer(Z isomer) has the H atoms on each carbon on the same side; the trans isomer( E isomer) has the H atoms on each carbon on different sides.

Question 5

Homolytic fission

Answer 5

Homolytic fission is the breaking of a covalent bond, with one of the bonded electrons going to each atom, forming two radicals.

Question 6

Radical

Answer 6

Radical is a species with an unpaired electron.

Question 7

Heterolytic fission

Answer 7

Heterolytic fission is the breaking of a covalent bond with both of the bonded electrons going to one of the atoms, forming a cation and an anion.

Question 8

Nucleophile

Answer 8

Nucleophile is an atom(or group of atoms) that is attracted to an electron-deficient centre or atom, where it donates a pair of electrons to form a new covalent bond.

Question 9

Electrophile

Answer 9

An electrophile is an atom(or group) that is attracted to an electron-rich centre or atom, where it accepts a pair of electrons to form a new covalent bond.

Question 10

Addition reaction

Answer 10

An addition reaction is a reaction in which a reactant is added to an unsaturated molecule to make saturated molecule.

Question 11

Substitution reaction

Answer 11

A substitution reaction is a reaction in which an atom or group of atoms is replaced with a different atom or group of atoms.

Question 12

Elimination reaction

Answer 12

An elimination reaction refers to the removal of a molecule from a saturated molecule to make a unsaturated molecule.

Question 13

radical substitution

Answer 13

Radical substitution is a type of substitution reaction in which a radical replaces a different atom or group of atoms.

Question 14

Mechanism

Answer 14

Mechanism is a sequence of steps showing the path taken by electrons in a reaction.

Question 15

Initiation

Answer 15

Initiation is the first step in a radical substitution in which the free radicals are generated by ultraviolet light.

Question 16

Propagation

Answer 16

Propagation is the two repeated steps in radical substitution that build up the products in a chain reaction.

Question 17

Termination

Answer 17

Termination is the step at the end of a radical substitution when two radicals combine to form a molecule.

Question 18

Pi-bond

Answer 18

A pi-bond is the reactive part of a double bond formed above and below the plane of the bonded atoms by sideways overlap of p-orbitals.

Question 19

Electrophilic addition

Answer 19

Electrophilic addition is a type of addition reaction in which an electrophile is attracted to an electron-rich centre or atom,where it accepts a pair of electrons to form a new covalent bond.

Question 20

Carbocation

Answer 20

Carbocation is an organic ion in which a carbon atom has a positive charge.

Question 21

Curly arrow

Answer 21

A curly arrow is a symbol used in reaction mechanisms to show the movement of an electron pair in the breaking or formation of a covalent bond.