Naming molecules/organic chem

Question 1

Organic chemistry

Answer 1

Study of carbon and its many carbons

Question 2

Why can carbon form many different compounds (allotropes)

Answer 2

Has 4 electrons in outer shell meaning it can form covalent bonds with four different atoms

Question 3

Why are hydrocarbons good fuels

Answer 3

Only has hydrogen and carbon atoms, Make good fuels due to their covalent bonds which store a large amount of energy

Question 4

What happens in a reaction of oxygen and hydrocarbons

Answer 4

releases CO2, H20 (gas), and energy (exothermic), in a limited supply of oxygen releases CO and H20 (gas)(incomplete combustion reaction)

Question 5

Homologous series

Answer 5

Differs by -CH2- from previous member, have similar structure, chemical properties and general formula, have a pattern to their physical properties

Question 6

Structural isomers

Answer 6

Occurs in alkanes that have 4+ carbon atoms, Same molecular formula but different arrangement of atoms

Question 7

Parent chain

Answer 7

Longest continuous chain of carbon,number of carbons in parent chain= prefix

Question 8

Substituent groups

Answer 8

Atoms or groups other than hydrogen on the molecule

Question 9

Alkanes

Answer 9

Only single bonds, saturated hydrocarbons, non-polar, usually follows formula of CnH2n+2

Question 10

Bonding in alkanes

Answer 10

Strong covalent bonds that increase as the size of the molecule increases meaning it has a high melting and boiling point in larger molecules, Weak intermolecular forces meaning lower melting and boiling point in smaller molecules, dispersion forces increase as mass of molecule increases

Question 11

Alkenes

Answer 11

At least one double bond, usually follows formula of CnH2n

Question 12

Cis-trans (geometric) isomers of alkenes

Answer 12

Joined in same arrangement but have a different arrangement in space due to the double bond between two atoms which keeps them in a fixed position, Two atoms joined by a single bond can rotate freely around the bond

Question 13

Cis isomers

Answer 13

same group on each carbon is located on the same side of the double bond

Question 14

Trans isomers

Answer 14

same group on each carbon is located on opposite sides of the double bond

Question 15

Properties of alkanes (7)

Answer 15

Colorless, Low density, Non-polar (no charge), Insoluble in water, Low melting and boiling point, Mostly inert but can react with halogens in UV light, Combust easily (exothermic)

Question 16

How do you test for alkenes/alkanes

Answer 16

Use bromine solution, alkanes will have no change in colour, alkenes will decolorise the solution

Question 17

Properties of alkenes (7)

Answer 17

Colourless, Non-polar (no charge), Insoluble in water, Low melting and boiling points, More reactive, Undergo addition reactions, Combust easily

Question 18

Addition reactions

Answer 18

occurs in alkenes where the double bond is broken and other atoms are added on, can be done with: hydrogen, halogens, hydrogen halides and water

Question 19

Benzenes (4)

Answer 19

C6H6- 6 carbon atoms joined in a ring each bonded to 1 hydrogen atom, Stable as the bonds are of equal strength, Have delocalised electrons which move through the ring, Aromatic- have sweet, pleasant aroma’s

Question 20

Properties of benzenes

Answer 20

Colourless liquid, Aromatic odour, Density is less than water, Non polar, Insoluble in water, Toxic, Volatile and high flammable, Combust with a black sooty flame

Question 21

Substitution reactions

Answer 21

Alkanes and benzenes react with halogens in UV light, Halogen atom replaces a hydrogen atom, if there is excess halogen further substitution may take place, Reaction can continue until all hydrogens have been substituted

Question 22

Saturated

Answer 22

can’t add anymore hydrogens as there are only single bonded, alkanes

Question 23

Unsaturated

Answer 23

can add more hydrogens by breaking double bond, alkenes