Question

1. an unknown organic compound p has the molecular formula \\(c_2h_6o\\). some information about the compound is shown.

• p can be made by fermentation process.
• p can be oxidised to form q.
• p reacts with q to form r and water.

which of the following combinations gives the correct homologous series for p, q and r?

\

$$\begin{array}{|c|c|c|c|} \\hline & p & q & r \\\\ \\hline a & \\text{alcohol} & \\text{carboxylic acid} & \\text{ester} \\\\ b & \\text{alkene} & \\text{alcohol} & \\text{carboxylic acid} \\\\ c & \\text{alkane} & \\text{alkene} & \\text{alcohol} \\\\ d & \\text{carboxylic acid} & \\text{ester} & \\text{alkane} \\\\ \\hline \\end{array}$$

Explanation:

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"concepts_used": [
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<reasoning>

Identify compound P

Using the Fermentation of Glucose knowledge point
\[

$$\begin{aligned} &\text{Formula: } \text{C}_2\text{H}_6\text{O}\\ &\text{Fermentation: } \text{C}_6\text{H}_{12}\text{O}_6 \xrightarrow{\text{yeast}} 2\text{C}_2\text{H}_5\text{OH} + 2\text{CO}_2\\ &\text{P is ethanol, which belongs to the alcohol homologous series.} \end{aligned}$$

\]

Identify compound Q

Using the Alcohol Oxidation knowledge point
\[

$$\begin{aligned} &\text{Oxidation: } \text{CH}_3\text{CH}_2\text{OH} + 2[\text{O}] ightarrow \text{CH}_3\text{COOH} + \text{H}_2\text{O}\\ &\text{Q is ethanoic acid, which belongs to the carboxylic acid homologous series.} \end{aligned}$$

\]

Identify compound R

The reaction between an alcohol and a carboxylic acid in the presence of an acid catalyst produces an ester and water.
\[
\text{CH}_3\text{CH}_2\text{OH} + \text{CH}_3\text{COOH}
ightleftharpoons \text{CH}_3\text{COOCH}_2\text{CH}_3 + \text{H}_2\text{O}
\]
Therefore, compound R is ethyl ethanoate, which belongs to the ester homologous series.

Match with options

Comparing our identified homologous series for P, Q, and R with the table:

• P: alcohol
• Q: carboxylic acid
• R: ester

This matches row A.
</reasoning>

<answer>
<mcq-correct>(A) P: alcohol, Q: carboxylic acid, R: ester</mcq-correct>
<mcq-option>(B) P: alkene, Q: alcohol, R: carboxylic acid</mcq-option>
<mcq-option>(C) P: alkane, Q: alkene, R: alcohol</mcq-option>
<mcq-option>(D) P: carboxylic acid, Q: ester, R: alkane</mcq-option>
</answer>

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Answer:

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<reasoning>

Identify compound P

Using the Fermentation of Glucose knowledge point
\[

$$\begin{aligned} &\text{Formula: } \text{C}_2\text{H}_6\text{O}\\ &\text{Fermentation: } \text{C}_6\text{H}_{12}\text{O}_6 \xrightarrow{\text{yeast}} 2\text{C}_2\text{H}_5\text{OH} + 2\text{CO}_2\\ &\text{P is ethanol, which belongs to the alcohol homologous series.} \end{aligned}$$

\]

Identify compound Q

Using the Alcohol Oxidation knowledge point
\[

$$\begin{aligned} &\text{Oxidation: } \text{CH}_3\text{CH}_2\text{OH} + 2[\text{O}] ightarrow \text{CH}_3\text{COOH} + \text{H}_2\text{O}\\ &\text{Q is ethanoic acid, which belongs to the carboxylic acid homologous series.} \end{aligned}$$

\]

Identify compound R

The reaction between an alcohol and a carboxylic acid in the presence of an acid catalyst produces an ester and water.
\[
\text{CH}_3\text{CH}_2\text{OH} + \text{CH}_3\text{COOH}
ightleftharpoons \text{CH}_3\text{COOCH}_2\text{CH}_3 + \text{H}_2\text{O}
\]
Therefore, compound R is ethyl ethanoate, which belongs to the ester homologous series.

Match with options

Comparing our identified homologous series for P, Q, and R with the table:

• P: alcohol
• Q: carboxylic acid
• R: ester

This matches row A.
</reasoning>

<answer>
<mcq-correct>(A) P: alcohol, Q: carboxylic acid, R: ester</mcq-correct>
<mcq-option>(B) P: alkene, Q: alcohol, R: carboxylic acid</mcq-option>
<mcq-option>(C) P: alkane, Q: alkene, R: alcohol</mcq-option>
<mcq-option>(D) P: carboxylic acid, Q: ester, R: alkane</mcq-option>
</answer>

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