Which pair from the following will not form an ideal solution?

Options

A. `C""Cl_4 +SiCl_4`
B. `H_2O+C_4H_9OH`
C. `C_2H_5Br +C_2H_5I`
D. `C_6H_(14)+C_7H_(16)`

Answer

To determine which pair of substances will not form an ideal solution, we need to understand the concept of ideal and non-ideal solutions, as well as Raoult's law.

### Step-by-Step Solution:

1. **Understand Ideal Solutions**:
An ideal solution is one that obeys Raoult's law, which states that the vapor pressure of the solution is directly proportional to the mole fraction of the solvent. For a solution to be ideal, the intermolecular forces between solute-solute, solvent-solvent, and solute-solvent must be similar.

**Hint**: Recall that ideal solutions have similar molecular structures and interactions.

2. **Identify Non-Ideal Solutions**:
A non-ideal solution does not obey Raoult's law. This can occur when there are significant differences in the intermolecular forces between the components, leading to either positive or negative deviations from Raoult's law.

**Hint**: Look for pairs with different molecular structures or strong intermolecular attractions.

3. **Analyze Each Pair**:
- **Pair 1: CCl4 and SiCl4**: Both are tetrahedral and have similar molecular structures. They are likely to form an ideal solution.
- **Pair 2: H2O and C4H9OH (Butanol)**: Water has strong hydrogen bonding, while butanol also has hydrogen bonding but with a different structure. The difference in their intermolecular forces suggests that this pair will not form an ideal solution.
- **Pair 3: C2H5Br and C2H5I**: Both have similar structures (ethyl group) and are halides. They are expected to behave ideally due to similar intermolecular forces.
- **Pair 4: C6H14 and C7H16**: Both are alkanes with similar structures and interactions, indicating they will also behave ideally.

**Hint**: Compare the molecular structures and types of bonding in each pair.

4. **Conclusion**:
The pair that will not form an ideal solution is **H2O and C4H9OH**. This is due to the differences in their molecular structure and the nature of their intermolecular forces, which leads to deviations from Raoult's law.

**Final Answer**: H2O and C4H9OH will not form an ideal solution.