Question

Water is produced from the reaction of hydrogen and oxygen gas, according to the equation below. What is the excess reactant in the reaction of 4.2 moles of hydrogen with 3.0 moles of oxygen?
2H2(g) + O2(g) = 2H2O(l)
Select one:
a.Water
b.Oxygen
c.No excess reactant
d.Hydrogen

Answer 1

Answer:

2H2O means two molecules of water(H2O)

Answer 2

Answer:

b.Oxygen

this is the excess reactant

Why?

2 moles of hydrogen react with 1 mole of oxygen. So, 4.2 moles of hydrogen would need 2.1 moles of oxygen. There are 3.0 moles of oxygen. So, there are 0.9 moles of oxygen in excess.