Final answer:
Pairs of compounds that are likely to form homogeneous solutions are those with similar polarities. Pentane and hexane will mix since both are nonpolar hydrocarbons. Lithium nitrate and water will also form a homogeneous solution since LiNO3 is ionic and soluble in polar H2O.
Step-by-step explanation:
When predicting whether pairs of compounds will form homogeneous solutions, the key principle is 'like dissolves like,' meaning that substances with similar polarity tend to be miscible. Let's evaluate the pairs listed:
- CH₃OH and CH₃CH₂CH₂CH₂CH₃: Methanol (CH₃OH) is a polar molecule that is capable of hydrogen bonding, while pentane (CH₃CH₂CH₂CH₂CH₃) is nonpolar. They would not be expected to form a homogeneous solution due to their different polarities.
- CH₃CH₂CH₂CH₂CH₃ and CH₃CH₂CH₂CH₂CH₂CH₃: Pentane and hexane are both nonpolar hydrocarbons and should form a homogeneous solution.
- LiNO₃ and H₂O: Lithium nitrate (LiNO₃) is an ionic compound that dissolves well in water (H₂O), a polar solvent, thus forming a homogeneous solution.
- CBr₄ and H₂O: Carbon tetrabromide (CBr₄) is a nonpolar molecule, and water is a polar solvent; thus, they would not form a homogeneous solution.
Therefore, the pairs we would expect to form homogeneous solutions are CH₃CH₂CH₂CH₂CH₃ and CH₃CH₂CH₂CH₂CH₂CH₃, as well as LiNO₃ and H₂O.