Question

Select the incorrect statement from the following option.

(a) Every pure solid crystalline substance has a characteristic and unique melting point

(b) Impure sample of substance has different melting point

(c) Two different pure substances have same melting points

(d) Melting point serves as the criteria of purity of a solid substance

The question was posed to me during an interview for a job.

Question is from Melting Point in portion Criteria of Purity and Characterisation of Materials of Engineering Chemistry I

Answer 1

Right choice is (c) Two different pure substances have same melting points

For explanation I would say: Two different pure substances have different melting points. All the other options are correct. Every pure solid crystalline substance has a characteristic and unique melting point and impure sample of substance has different melting point. Melting point serves as the criteria of purity of a solid substance.