9. Antimony is burned in oxygen to form antimony oxide. 4Sb+3O_(2)arrow 2Sb_(2)O_(3) How many moles of Sb_(2)O_(3) will be formed when you have 20.0 moles of oxygen gas? 10.0 moles 13.3 moles 15.5 moles 40.8 moles

The balanced chemical equation for the reaction is $4Sb+3O_{2}\rightarrow 2Sb_{2}O_{3}$. This tells us that 3 moles of oxygen gas react with 4 moles of antimony to produce 2 moles of antimony oxide. Therefore, the ratio of oxygen gas to antimony oxide is 3:2. If we have 20.0 moles of oxygen gas, we can use this ratio to find the number of moles of antimony oxide produced. <br /><br />First, we set up a proportion: $\frac{3 \text{ moles of } O_{2}}{2 \text{ moles of } Sb_{2}O_{3}} = \frac{20.0 \text{ moles of } O_{2}}{x \text{ moles of } Sb_{2}O_{3}}$. <br /><br />Next, we solve for x: $x = \frac{2 \text{ moles of } Sb_{2}O_{3} \times 20.0 \text{ moles of } O_{2}}{3 \text{ moles of } O_{2}} = 13.3 \text{ moles of } Sb_{2}O_{3}$. <br /><br />Therefore, 13.3 moles of antimony oxide will be formed when 20.0 moles of oxygen gas are used.