When performing a titration to measure the purity of a solvent, what conclusion can be drawn from narrow melting point ranges?

Narrow melting point ranges indicate that a substance is mostly pure because pure compounds typically have well-defined and sharp melting points. When a substance is pure, the intermolecular forces are uniform, leading to a consistent energy requirement for the transition from solid to liquid, which manifests as a narrow melting point range.

In contrast, impure substances usually exhibit broader melting point ranges due to the presence of different components, which disrupt the uniformity of the crystalline structure. These impurities can interfere with the melting process, causing a broader range of temperatures over which the solid will melt. Therefore, a narrow melting point range serves as a strong indicator of high purity in the substance being analyzed.

The other options would suggest either lack of purity or process-related issues that do not apply when a narrow range is observed.