Cambridge Secondary (7-9). Stage 9. MCE Science. Workbook - Unit 1: Photosynthesis and Transport in Plants - Question 4

In steps 5 and 6 of a leaf starch test, the boiled leaf is put into ethanol in a boiling tube, which is then stood in hot water. Suggest why steps 5 and 6 were important to carry out before doing the starch test.