Question

Selenium dioxide, a medicine that is used for the treatment of stroke, hardening of arteries, and cancers, is prepared by a reaction of selenium with hydrogen peroxide:

2H₂O₂ + Se → SeO₂ + 2H₂O

How many moles of H₂O₂ are required to produce 11g SeO₂ according to the equation?

Answer 1

$2H_2O_2 + Se → SeO_2 + 2H_2O\\$

11g of SeO₂ = 11/111 = ~0.1 mole

2 moles of H₂O₂ reacts with one mole of SeO₂

$\therefore$ 0.2 moles of H₂O₂ is needed for the reaction.