2 H2 (g) —> 2 H2O (g)

Calculate the mass of oxygen gas, O2, required to produce 12.90 moles of water, H20

Molar mass H2= 2.016 g/mol
Molar mass O2= 32.00 g/mol
Molar mass = 18.02 g/mol

mole=mass/molar mass

mass=mole×molar mass

mass=12.90mole×18g/mole

mass=232.2g

answer; i believe the correct answer is (solid gold);

8 m/s because for him to get the same amount of energy as ray is putting out, bobby, who weighs half as much as ray, needs to run twice as fast.