one mole KClO3 is heated in presence of MnO2. the produced oxygen is used in burning of Al .the oxide produced of AL will be

Potassium chlorate (KClO3) is used in the manufacture of oxygen in the presence of manganese oxide catalyst.
The reaction is as follows:
(heat in the presence of MnO2 catalyst)
2KClO3 -------------------------------------------------> 2KCl + 3O2

Therefore 2 moles of KClO3 produces 3 moles of oxygen.

Hence 1 mole of KClO3 will give 1.5 moles of oxygen. Using this to form AlO3 will give.;

2Al + 3O2 --------> 2AlO3

Therefore 3moles of O2 give 2moles of AlO3.

Hence 1.5moles will give (2x1.5)/3 = 3/3 = 1

AlO3 produced is 1mole