In the reaction 2H2 + O2 --> 2H2O, how many moles of oxygen are required to fully react with 6.0 mol of hydrogen? A) 1.0 mol
B) 2.5 mol
C) 3.0 mol
D) 7.5 mol

Actually Welcome to the Concept of the Stochiometry.

Hence, here we can clearly see that, for 2 moles of Hydrogen, we need 1 mole of oxygen molecules,

so, then 6 moles of Hydrogen we need, 3 moles of Oxygen.

hence option c.) 3 mole

10 years is the answer

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )