Question

multiple choice 1 point
how can the purity of the isolated caffeine be confirmed?
by testing its color
by measuring its melting point
by observing its boiling point
by determining its ph

Explanation:

Pure substances have characteristic and sharp melting - points. Impurities lower and broaden the melting - point range. So, measuring the melting point can confirm the purity of isolated caffeine. Color is not a reliable purity indicator as impurities may not change color significantly. Boiling point can be affected by pressure and is not as straightforward as melting point for purity determination. pH is related to acidity or basicity and not a measure of purity for caffeine.

Answer:

B. By measuring its melting point