sc23, alcohols and carboxylic acids (paper 2) Flashcards
what is the molecular formula for alcohol
C n H 2n+1 OH
how can ethanol be oxidised to ethanoic acid
- by chemicals called oxidising agents or
- the actions of microbes
what is the mian acid in vinegar
ethanoic acid
what is an alcohol
an alcohol forms a homologous series of compounds
what do the names of alcohol end in
anol
what functional group do all alcohols have
O-H (hydroxyl-
true or false: alcohols have similar chemical properties
true
true or false: alcohols don’t have similar chemical properties
false
true or false: alcohols show a gradual variation in physical properties
true
true or false: alcohols don’t show a gradual variation in physical properties
false
what does the molecular formula of alcohol differ by
C H 2
how is ethanol produced
from carbohydrates in aqueous solution by a process called fermentation
where can the carbohydrates come from for producing ethanol
- fruit (e.g grape)
- breakdown os starch (from wheat or barley)
what single-celled fungus helps speed up the production of ethanol by providing enzymes
yeast, a single-celled fungus
give the word equation for the production of ethanol
glucose –> ethanol + carbon dioxide
give the symbol equation for the production of ethanol
C6H12O6 (aq) –> 2 C2H6OH + 2 CO2
what is the optimum tempurature for fermentation
35
what happens when oxygen is present during fermentation
- aerobic respiration happens instead of anaerobic respiration
- so it produces only carbon dioxide and water
how can we obtain the ethanol in the mixture with water
- fractional distillation
- chemically absorb the last small amount of water
what is a carboxylic acid
carboxylic acids form a homologous series of compounds
what do the names of carboxylic acids end in
anoic
what functional group do all carboxylic acids have
= O
C
- O - H
carboxyl
true or false: carboxylic acids have similar chemical properties
true
true or false: carboxylic acids don’t have similar chemical properties
false
true or false: carboxylic acids don’t show a gradual variation in physical properties
false
true or false: carboxylic acids show a gradual variation in physical properties
true
what does the molecular formula of carboxylic acids differ by
CH2
what is the molecular formula for carboxylic acids
C n -1 H 2n-2 COOH
are carboxylic acids weak or strong acids, why?
weak as they only partially dissociate into ions when they dissolve in water
give the word equation for the dissociation of acids
carboxylic acid <–> carboxoate ion + hydrogen ion
what three properties do carboxylic acids have in common with acids
- react with carbonates to produce salt, water and carbon dioxide
- react with reactive metals to produce a salt and hydrogen
- dissolve in water to produce acidic solutions
