1. (a) The diagram on the right shows part of an arrangement of apparatus and chemicals used to prepare ethene (C2H4) by dehydrating ethanol using a catalyst - Leaving Cert Chemistry - Question 1 - 2022
Question 1
1. (a) The diagram on the right shows part of an arrangement of apparatus and chemicals used to prepare ethene (C2H4) by dehydrating ethanol using a catalyst.
(i) C... show full transcript
Worked Solution & Example Answer:1. (a) The diagram on the right shows part of an arrangement of apparatus and chemicals used to prepare ethene (C2H4) by dehydrating ethanol using a catalyst - Leaving Cert Chemistry - Question 1 - 2022
Step 1
Copy and complete the diagram by labeling the locations of the ethanol and the catalyst and showing how the ethene gas could have been collected.
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
In the diagram, label the left container as 'ethanol' and the apparatus above it as 'catalyst' (specifically aluminum oxide, Al2O3). The ethene gas could have been collected using a gas syringe positioned at the outlet of the apparatus.
Step 2
Identify the catalyst used in this preparation.
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 catalyst used in this preparation is aluminum oxide (Al2O3).
Step 3
Describe how you could carry out a test for unsaturation on a sample of ethene.
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
To test for unsaturation in ethene, you can mix the gas with bromine water. When ethene is bubbled through bromine water, the reddish-brown color of the bromine will disappear, indicating that the ethene is unsaturated.
Step 4
Describe the appearance at room temperature of (i) phenylmethanol.
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
At room temperature, phenylmethanol appears as a colorless liquid with a pale yellow tint.
Step 5
Describe the appearance at room temperature of (ii) benzoic 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
Benzoic acid is typically a white crystalline solid at room temperature.
Step 6
Which of these reagents (iii) was added after the oxidation stage to reduce the MnO2 to soluble Mn2+ ions?
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
Sodium sulfite (Na2SO3) was added after the oxidation stage to reduce MnO2 to soluble Mn2+ ions.
Step 7
What colour change was observed as (iv) the oxidation of the phenylmethanol took place?
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
As the oxidation of phenylmethanol took place, the color of the solution changed from colorless to purple due to the presence of KMnO4.
Step 8
What colour change was observed as (vi) the MnO2 was converted to Mn2+?
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
As the MnO2 was converted to Mn2+, the solution became brown (muddy), eventually leading to a colorless state.
Join the Leaving Cert students using SimpleStudy...
