Paper 4 · November 2004 · Enzymes

In a Benedict's test, five glucose standards from 0.001 to 0.005 mol/dm3 are each mixed with Benedict's solution and heated in a boiling water bath for 5 minutes. Which colour is expected for the LOWEST standard, 0.001 mol/dm3?

AGreen

BDark orange

CLight orange

DOrange

Explanation

A Benedict's test gives a colour scale that runs from green (least reducing sugar) through yellow and orange to a dark orange/brick-red precipitate (most reducing sugar); the lowest standard gives the smallest colour change, green.

Derived from ZIMSEC Biology 9190/4 Paper 4, November 2004, Q1

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