A test tube containing a straight chain organic acid X, ethanol and a catalyst is heated in a water bath, as illustrated below - NSC Physical Sciences - Question 2 - 2018 - Paper 2
Question 2
A test tube containing a straight chain organic acid X, ethanol and a catalyst is heated in a water bath, as illustrated below.
Organic compound Y is produced accor... show full transcript
Worked Solution & Example Answer:A test tube containing a straight chain organic acid X, ethanol and a catalyst is heated in a water bath, as illustrated below - NSC Physical Sciences - Question 2 - 2018 - Paper 2
Step 1
2.1 Give a reason why the test tube is heated in a water bath instead of directly over the flame.
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Answer
The test tube is heated in a water bath to provide a controlled and even heat source. This method avoids the risk of overheating or igniting the flammable ethanol, ensuring a safer reaction environment.
Step 2
2.2.1 Type of reaction that takes place here
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The type of reaction that takes place is esterification, a process where an alcohol reacts with an acid to form an ester and water.
Step 3
2.2.2 FORMULA of the catalyst needed
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The formula of the catalyst needed for the reaction is H₂SO₄ (sulfuric acid).
Step 4
2.2.3 Homologous series to which compound Y belongs
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Compound Y belongs to the ester homologous series.
Step 5
2.3 Determine the molecular formula of compound Y.
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The molecular formula of compound Y can be derived from its molar mass of 144 g·mol⁻¹. Given the empirical formula C₄H₈O, the molecular formula is C₈H₁₆O₂.
Step 6
2.4 Write down the IUPAC name of compound Y.
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The IUPAC name of compound Y, which is an ester derived from ethanol and organic acid X, is ethyl hexanoate.
Step 7
2.5 Write down the structural formula of the organic acid X.
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The structural formula of organic acid X, which is a straight-chain carboxylic acid with the empirical formula C₄H₈O₂, is:
O
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H₃C—C—C—C—OH
The structural formula represents butanoic acid, which corresponds to the given empirical formula.
