Alkanes, alcohols and carboxylic acids are homologous series studied in organic chemistry - Leaving Cert Chemistry - Question 8 - 2012
Question 8
Alkanes, alcohols and carboxylic acids are homologous series studied in organic chemistry.
(a) Explain the underlined term.
(b) In the case of any two of the homol... show full transcript
Worked Solution & Example Answer:Alkanes, alcohols and carboxylic acids are homologous series studied in organic chemistry - Leaving Cert Chemistry - Question 8 - 2012
Step 1
Explain the underlined term.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The term 'homologous series' refers to a group of organic compounds that share a common structural feature and have similar chemical properties. Each member of a homologous series differs from the next by a constant unit, typically a -CH2- group. This results in a gradual change in physical properties, such as boiling points, as the molecular size increases.
Step 2
In the case of any two of the homologous series above, give the name and structural formula of one member of the series.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Alkanes:
Name: Ethane
Structural Formula: C2H6 (or CH3-CH3)
Alcohols:
Name: Ethanol
Structural Formula: C2H5OH (or CH3CH2OH)
Step 3
Give one common use for each of the compounds you have named in (b).
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Ethane: Used as a fuel in heaters and cooking appliances.
Ethanol: Commonly used as an alcoholic beverage and as a solvent in various industrial applications.
Step 4
What type of organic reaction is involved?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The reaction involved is called oxidation. In this process, alcohols are converted to carboxylic acids by the addition of oxygen or the removal of hydrogen.
Step 5
Give the name or formula of the gas produced when moist sodium carbonate (Na2CO3) reacts with a carboxylic acid.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The gas produced is carbon dioxide (CO2).
Step 6
What simple test could be carried out on this gas to confirm its identity?
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To confirm the identity of carbon dioxide, you can pass the gas through lime water (a dilute solution of calcium hydroxide). If carbon dioxide is present, it will react to form calcium carbonate, which makes the lime water turn milky.
Join the Leaving Cert students using SimpleStudy...
