F322 - Basic Concepts and Hydrocarbons

Question 0

What is a molecular formula?

Answer 0

The actual number of atoms of each type of element present in a molecule.

Question 1

What is an empirical formula?

Answer 1

The simplest whole-number ratio of atoms of each element present in a compound.

Question 2

What is a general formula?

Answer 2

The simplest algebraic formula of a member if a homologous series.

Question 3

What is a structural formula?

Answer 3

The minimal detail that shows the arrangement of atoms in a molecule.

Question 4

What is a displayed formula?

Answer 4

The relative positioning if atoms and the bonds between them for a molecule.

Question 5

What is a skeletal formula?

Answer 5

The simplified organic formula, shown by removing hydrogen atoms from alkyl chains, leaving just a carbon skeleton and associated functional groups.

Question 6

What is a homologous series?

Answer 6

A series of organic compounds having the same functional group but with each successive member differing by CH2.

Question 7

What is meant by the term functional group?

Answer 7

A group of atoms responsible for the characteristic reactions of a compound (its chemical properties).

Question 8

What are the names of the first ten alkanes in order?

Answer 8

Methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane.

Question 9

What is meant by the term structural isomers?

Answer 9

Compounds with the same molecular formula but different structural formulae.

Question 10

What is meant by the term stereoisomers?

Answer 10

Compounds with the same structural formula but a different arrangement of atoms in space.

Question 11

What are the features of a compound which make it exhibit stereoisomerism?

Answer 11

C=C Double bond (restricts rotation) and having two different groups attached to each C in the C=C double bond.

Question 12

What is homolytic fission?

Answer 12

Breaking of a covalent bond to form two radicals.

Question 13

What is heterolytic fission?

Answer 13

The breaking of a covalent bond to form a cation and an anion.

Question 14

What do curly arrows represent in a reaction mechanism?

Answer 14

The movement of an electron pair to show the breaking or making of a covalent bond.

Question 15

How is percentage yield calculated?

Answer 15

Actual yield x 100/theoretical yield

Question 16

What is atom economy?

Answer 16

The sum of the molecular mass of the desired products x 100%/sum of molecular masses of all products (or reactants)

Question 17

Why is the atom economy of addition reactions 100%?

Answer 17

They only produce one product which is the desired product. No waste products are formed.

Question 18

How could you increase the atom economy of a substitution reaction?

Answer 18

Find a use for the wasteful products.

Question 19

What is a hydrocarbon?

Answer 19

A compound that contains carbon and hydrogen ONLY.

Question 20

What does the term saturated hydrocarbon mean?

Answer 20

Compound that contains only C-C single bonds (no C=C double bonds).

Question 21

How is fractional distillation used to separate crude oil?

Answer 21

Separates based in differing boiling points. Low boiling points are collected at the top of the column and high boiling points at the bottom.

Question 22

What is the shape and bond angle around the carbons in an alkane?

Answer 22

Tetrahedral and 109.5

Question 23

Why do the boiling points of alkenes increase with increasing chain length?

Answer 23

There are more points of surface contact and therefore more van der Waals’ forces.

Question 24

Why do the boiling points of alkenes decrease with increased branching?

Answer 24

There are less points of surface contact and therefore fewer van der Waals’ forces.

Question 25

What causes incomplete combustion?

Answer 25

Insufficient supply (lack) of oxygen

Question 26

Why is carbon monoxide dangerous?

Answer 26

It bonds to the iron of haemoglobin in the blood in preference to oxygen.

Question 27

What is cracking?

Answer 27

Taking long chain hydrocarbons and breaking them into smaller pieces including branched isomers and alkenes.

Question 28

Why do we process hydrocarbons using cracking?

Answer 28

Turns larger less useful fractions into more useful smaller fractions suitable for fuels and the production of polymers.

Question 29

What is a radical?

Answer 29

A species with an unpaired electron.

Question 30

What is required for the formation of a halogenoalkane from a halogen molecule?

Answer 30

Ultraviolet radiation

Question 31

What are the limitations of using free radical substitution for making halogenoalkanes?

Answer 31

Further substitution can take place forming a mixture of products.

Question 32

What is an unsaturated hydrocarbon?

Answer 32

Contains a C=C double bond

Question 33

How is a pi bond formed?

Answer 33

The overlap of adjacent p orbitals.

Question 34

What is the shape and bond angle around each of the carbon atoms in the C=C double bond?

Answer 34

Trigonal planar and 120.

Question 35

Where do small molecules et added during an addition reaction?

Answer 35

Across the C=C double bond.

Question 36

What is meant by the term electrophile?

Answer 36

An electron pair acceptor

Question 37

What is addition polymerisation?

Answer 37

Forming a polymer by a repeated addition reaction.

Question 38

What is a monomer?

Answer 38

The small molecule used to build a polymer molecule.

Question 39

What are the reagents in the manufacture if margarine?

Answer 39

Unsaturated vegetable oils, hydrogen and a nickel catalyst.

Question 40

How can waste polymers be processed?

Answer 40

Sort and recycle, combusted for energy production, and as a feedstock for cracking to make other plastics.

Question 41

How can toxic HCl be removed from the atmosphere?

Answer 41

React with an alkali

Question 42

What type of polymers are being produced to help minimise environmental damage?

Answer 42

Biodegradable polymers, compostable polymers and photodegradable polymers