A solution of acetone in ethnol

Options

A. Obeys Raoult's law
B. Shows a negative deviation from Raoult's law
C. Shows a positive deviation from Raoult's law
D. Behaves like a near ideal solution

Answer

To determine whether a solution of acetone in ethanol shows positive deviation, negative deviation, or obeys Raoult's law, we can follow these steps:

### Step 1: Identify the nature of acetone and ethanol
- **Acetone (CH₃C(=O)CH₃)** is a polar molecule due to the presence of a carbonyl group (C=O), which creates a dipole moment.
- **Ethanol (CH₃CH₂OH)** is also a polar molecule and has the ability to form hydrogen bonds due to the presence of the hydroxyl group (–OH).

**Hint:** Look for the functional groups in the molecules to determine polarity and potential interactions.

### Step 2: Analyze the intermolecular forces
- In ethanol, strong hydrogen bonding occurs between the hydroxyl groups of different ethanol molecules.
- In acetone, the primary intermolecular forces are dipole-dipole interactions, which are weaker than hydrogen bonds.

**Hint:** Compare the strength of the intermolecular forces in each component.

### Step 3: Consider the interactions when mixed
- When acetone and ethanol are mixed, the hydrogen bonds in ethanol are disrupted. This leads to a decrease in the attractive forces between ethanol molecules.
- The new interactions formed (between acetone and ethanol) are dipole-dipole interactions, which are weaker than the hydrogen bonds that were present in pure ethanol.

**Hint:** Think about how mixing affects the existing intermolecular forces.

### Step 4: Determine the type of deviation from Raoult's law
- If the interactions between the components (acetone and ethanol) are weaker than those in the pure components, the solution will exhibit positive deviation from Raoult's law.
- Since the hydrogen bonding in ethanol is stronger than the dipole-dipole interactions between acetone and ethanol, the overall interaction in the solution (AB) is weaker than the interactions in the pure components (AA and BB).

**Hint:** Recall the conditions for positive and negative deviations: positive deviation occurs when the solution's interactions are weaker than those in the pure components.

### Conclusion
Based on the analysis, the solution of acetone in ethanol shows positive deviation from Raoult's law.

**Final Answer:** The solution of acetone in ethanol shows positive deviation from Raoult's law.