Study the reaction scheme below and answer the questions that follow - Leaving Cert Chemistry - Question 8 - 2014
Question 8
Study the reaction scheme below and answer the questions that follow.
(a) Give the systematic (IUPAC) names for W and X.
(b) Describe, including a labelled diagram... show full transcript
Worked Solution & Example Answer:Study the reaction scheme below and answer the questions that follow - Leaving Cert Chemistry - Question 8 - 2014
Step 1
Give the systematic (IUPAC) names for W and X.
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 systematic name for W is ethene, and for X is ethanol.
Step 2
Describe, including a labelled diagram, how you would prepare W using reaction A and how you would collect it in test-tubes.
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
To prepare W (ethene) from X (ethanol), you would heat ethanol with aluminum oxide (Al2O3) as a catalyst. The setup consists of a boiling apparatus connected to a water condenser to collect the ethene.
Diagram of Setup:
Apparatus: A test tube stands vertically, heated at the bottom.
Generation: Ethanol soaked in glass wool is heated with Al2O3.
Collection: Ethene moves through a tube into a water container, where it can be collected in inverted test tubes.
Ensure you first soak the glass wool in ethanol, then heat it gently.
Safety Tip: Handle the aluminum oxide carefully as it can be reactive.
Step 3
Which of the compounds
(i) is found in vinegar?
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
The compound Z, which is acetic acid, is found in vinegar.
Step 4
Which of the compounds
(ii) is often produced by the fermentation of sugars in fruit, e.g., grapes?
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
Compound Y, which is ethanol, is often produced by the fermentation of sugars in fruits like grapes.
Step 5
Which of the compounds
(iii) produces a red precipitate when heated with Fehling's solution?
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
Compound X, which is ethanol, produces a red precipitate when heated with Fehling's solution.
Step 6
What gas is produced when an aqueous solution of compound Z, a carboxylic acid, reacts with solid sodium carbonate (Na2CO3)?
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
The gas produced is carbon dioxide (CO2).
Step 7
How could you test for this gas?
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
To test for carbon dioxide, you can bubble it through limewater (calcium hydroxide solution). The limewater will turn milky due to the formation of calcium carbonate.
Step 8
What other carboxylic acid occurs as an irritant in the stings of ants and nettles?
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
The other carboxylic acid that occurs as an irritant in the stings of ants and nettles is methanoic acid (formic acid).
Join the Leaving Cert students using SimpleStudy...
