organic chemistry 4/3/24

Question 1

what is a homologous series?

2 or 3 things

Answer 1

a) a group of compounds which behave in a similar way chemically
b) as a result of being from the same functional group
c) same general formula

Question 2

give examples of 3 homologous series

Answer 2

• alkanes
• alkenes
• alcohols

Question 3

what does the start of each name of a compound in a homologous series indicate?

e.g. METHane, BUTene, ETHanol

Answer 3

number of carbons

Question 4

a homologous series is a group of compounds which have the same ____ formula

Answer 4

general formula

Question 5

alkanes: the formula of each molecule in the series in creases by a [___?___] each time

Answer 5

CH2

Question 6

general formula for alkanes

Answer 6

CnH2n+2, e.g. propANE, C3H8

Question 7

as the number of carbons increases in a homologous series, the boiling and melting points [_?___]

Answer 7

also increase

Question 8

compounds in a homologous series have similar [___?___] properties

Answer 8

chemical properties

Question 9

as the chain length of the compounds in a homologous series increases, so does the [?]

Answer 9

number of carbons

Question 10

give a homologous series whose compounds are only hydrocarbons

Answer 10

alkAnes

Question 11

what are hydrocarbons?

Answer 11

compounds consisting of carbon and hydrogen ONLY

Question 12

alkanes: every carbon bond has FOUR [?] COVALENT bonds [??]

Answer 12

[?] = SINGLE
[??] = SATURATED

Question 13

what does saturated mean?

Answer 13

containing ONLY SINLE covalent bonds (no double or tripple or whatever)

Question 14

all alkanes have a [?] at each end of the molecule

Answer 14

CH3

Question 15

in which homologous series is there always a CH3 at each end of the molecule?

Answer 15

alkanes

Question 16

how can you remember the order/numbers of the start of the names of molecules?

e.g. METH, ETH, etc.

Answer 16

meth
eth
prop
but
pent
.
monkeys
eat
proper
butiful
penuts

Question 17

general formula definition

Answer 17

“a mathematical formula that describes any member of a homologous series”

(the formula with 2n and things like that)

Question 18

general formula: applied to ethane

Answer 18

CnH2n+2

Question 19

molecular formula definition

Answer 19

“the actual number of atoms of each element of a compound”

Question 20

molecular formula: applied to ethane

Answer 20

C2H6

Question 21

empirical formula definition

Answer 21

“the simplest whole number ratio of atoms of each element in a compound”

Question 22

empirical formula: applied to ethane

Answer 22

CH3

Question 23

structural formula definition

Answer 23

“a written representation of how the carbon atoms are arranged”

Question 24

structural formula: applied to ethane

Answer 24

CH3CH3

Question 25

displayed formula definition

Answer 25

"shows how the atoms are arranged and ALL THE BONDS" | like when you draw the molecule

Question 26

are alkenes more or less reactive than alkanes? why?

Answer 26

alkenes are MORE reactive than alkanes alkenes have a double covalent bond (they are unsaturated) this double bond makes the molecule very reactive

Question 27

# from educake Ethanol can be produced from ethene using steam. What is this process known as?

Answer 27

hydration (Organic reactions in which water is a reactant are often referred to as "hydration reactions".)

Question 28

# from educake What is needed to speed up the reaction of ethene and water to make ethanol?

Answer 28

phosphoric acid (as a catalyst)

Question 29

# from educake What is the symbol of the functional group that all alcohols contain?

Answer 29

-OH

Question 30

# from educake Do carboxylic acids have double bonds between carbon atoms?

Answer 30

No (there is only a carbon-oxygen double bond)

Question 31

# from educake name the alcohol found in alcoholic drinks

Answer 31

ethanol

Question 32

# from educake what type of reaction is used to produce ethanoic acid from ethanol?

Answer 32

oxidation

Question 33

# from educake name the gas produced when carboxylic acids reacts with carbonates

Answer 33

carbon dioxide (all acids react with carbonates to form carbon dioxide)

Question 34

# from educake which of the following is an example of a carboxylic acid? * ethyl ethanoate * hydrochloric acid * butanoic acid * sodium propanoate

Answer 34

butanoic acid (all carboxylic acids end in '-anoic acid')

Question 35

# from educake What is the name of the carboxylic acid with the formula C3H7COOH? | (the 3 and 7 should be subscript)

Answer 35

butanoic acid (The compound has 4 carbon atoms, so it has the "but-" prefix. It is a carboxylic acid, so it has the "-anoic acid" ending.)

Question 36

# from educake what is the functional group of all carboxylic acids?

Answer 36

-COOH

Question 37

# from educake Which of the following is NOT needed for fermentation to produce ethanol? * yeast * light * water * sugar

Answer 37

light (Fermentation needs sugar, water and yeast. Light is not required.)

Question 38

# from educake What is the name of the type of polymerisation that involves the loss of small molecules, such as water?

Answer 38

condensation polymerisation

Question 39

# from educake name this substance: CH3CH2COOH

Answer 39

propanoic acid 3xC's = prop- -COOH = -anoic acid = propanoic acid

Question 40

# from educake Ethanol can be produced from ethene. What substance found in the earth do we obtain ethene from?

Answer 40

crude oil

Question 41

# from educake Vinegar is an aqueous solution of which substance?

Answer 41

ethanoic acid

Question 42

# from educake Look at the chemical equation shown below. Name the alcohol taking part in this reaction: 2 CH3OH (l) + 3 O2 (g) --> X (g) + 4 H2O (l)

Answer 42

* alcohol = methanol, HCOOH * (X = methanoic acid, because alcohol + O2 --> carboxylic acid)

Question 43

# from educake Alkenes react with steam in the presence of a ________ to produce an alcohol. What is the missing word in this sentence?

Answer 43

catalyst - a catalyst such as phosphoric acid must be present for this reaction

Question 44

# from educake Ethanol can be produced using yeast. What is this process called?

Answer 44

fermentation

Question 45

# from educake Fermentation is used to produce ethanol from a glucose solution. What process can be used to separate the ethanol from the fermentation mixture?

Answer 45

fractional distillation (this is a common method for separating mixtures of liquids)

Question 46

the ethanol produced from fermentation isn't very c----- so it needs to be d----- then p-----

Answer 46

concentrated so it needs to be distilled then purified

Question 47

# from educake In polyesters, one of the monomers has two COOH groups. What are the functional groups on the other monomer?

Answer 47

two -OH groups

Question 48

# from educake Ethanoic acid reacts with carbonates to produce water, a salt and carbon dioxide. Which of these substances creates the same products when reacting with carbonates? * ethanol * ethene * ethane * propanoic acid

Answer 48

**prpoanoic acid.** This reaction is typical of *carboxylic acids* reacting with *carbonates*, where the a**cid neutralizes the carbonate,** producing a salt, water, and carbon dioxide gas. **ALL ACIDS react with CARBONATES to form A SALT, H2O AND CO2**

Question 49

# from educake Methanoic acid is produced by oxidising... what?

Answer 49

methanol (Alcohols can be oxidised to produce the equivalent carboxylic acid. Methanol can be oxidised to methanoic acid.)

Question 50

# from educake What is advantage of making ethanol by fermentation?

Answer 50

the raw materials used are all renewable resources

Question 51

# from educake which of these is an advantage of making ethanol by fermentation: * it does not require a catalyst * it makes 100% pure ethanol * it is a fast continuous process * uses renewable resources ?

Answer 51

uses renewable resources: * sugar (sugar cane) is grown as a major crop around the world * yeast (which acts as a natural catalyst in fermentation reactions) is also easy to grow

Question 52

# from educake Alcohols can be reacted with which chemical to produce carboxylic acids?

Answer 52

acidifried potassium dichromate (aq)

Question 53

# from educake What is NOT a condition for making ethanol by **fermentation**: * temperature 30 degrees C * phosphoric acid catalyst * anaerobic conditions (no O2) * yeast catalyst ?

Answer 53

phosphoric acid catalyst is NOT required to make ethanol by fermentation, but IS NEEDED for the production of ethanol *from ethene and steam*.

Question 54

# from educake Ethanol is produced during fermentation. What is the other product? Give the name, not the formula.

Answer 54

* **carbon dioxide** * glucose → ethanol + carbon dioxide

Question 55

# from educake Which is NOT a condition for making ethanol by direct hydration: * anaerobic conditions * temperature of 300 degrees C * 60-70 atm pressure * phosphoric acid catalyst ?

Answer 55

you **don't** need ANAEROBIC CONDITIONS - this is only needed for production of ethanol by **fermentation**.

Question 56

# from educake When propanoic acid reacts with magnesium what is the name of the salt produced?

Answer 56

the salt produced is **magnesium propanoate**. The balanced chemical equation for this reaction is: 2CH3​CH2​COOH+Mg→(CH3​CH2​COO)2​Mg+H2​