Classify each of the following as… | Chemistry

Question 1 Report

Classify each of the following as physical change or a chemical change:

(a) fractional distillation of liquefied air;

(b) cracking of petroleum fractions;

(d) chromatographic separation of chlorophyll.

Answer

Answer Details

(a) Fractional distillation of liquefied air: physical change (the components are only separated by boiling point; no new substance is formed).
(b) Cracking of petroleum fractions: chemical change (large molecules are broken into new, smaller molecules).
(c) Conversion of rhombic sulphur to monoclinic sulphur: physical change (only a change in the crystalline form/allotrope; the substance is still sulphur).
(d) Chromatographic separation of chlorophyll: physical change (the pigments are merely separated; no new substance is formed).

Classify each of the following as physical change or a chemical change: (a) fractional distillation of liquefied air; (b) cracking of petroleum fractions; (...