Why do impurities lower melting point?
Understand the Problem
The question is asking about the effect of impurities on the melting point of substances. When impurities are present in a pure substance, they disrupt the orderly arrangement of particles, which can lower the energy required to change the state from solid to liquid, thereby decreasing the melting point.
Answer
Impurities disrupt the crystal lattice, causing a lower melting point.
Impurities lower the melting point by disrupting the crystal lattice of the solid, thereby requiring less energy to break the intermolecular forces.
Answer for screen readers
Impurities lower the melting point by disrupting the crystal lattice of the solid, thereby requiring less energy to break the intermolecular forces.
More Information
Impurities in a solid create irregularities in the crystal lattice, weakening the overall structure and thereby lowering the amount of energy required to initiate melting, which leads to a decreased melting point.
Tips
common mistakes include confusing the effect of impurities on melting and boiling points; impurities decrease melting point but can increase boiling point.
Sources
- How do impurities affect the melting point of a substance - tutorchase.com
- Why do impure solids melt at lower temperatures - Kirsop Labs - kirsoplabs.co.uk
- Effect of impurities on melting and boiling points - chemistry.stackexchange.com
