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 . 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. First, we set up a proportion: . Next, we solve for x: . Therefore, 13.3 moles of antimony oxide will be formed when 20.0 moles of oxygen gas are used.