Criteria for purity of organic solid is
(a) boiling point
(b) melting point
(c) specific gravity
(d) none of these
(b) melting point
Melting point is considered to be the best measure of purity of a substance.
When a purified sample is mixed with a small amount of pure compound , melting point of the mixture is determined.
If a substance is impure (contains impurities/other substance) the melting point of that substance will change.
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The purity percentage of a substance can be calculated by dividing the mass of the pure chemical by the total mass of the sample and multiplying this number by 100.
[Mass of pure chemical/total mass × 100]
