If 4.0 g of hydrogen and 10.0 g of oxygen are mixed according to the equation 2 h2 + o2 → 2 h2o, which is the limiting reagent?

From the equation, we can see that the molar ratio between hydrogen and oxygen is:
2 : 1

Next, we determine the moles of hydrogen and oxygen that are actually present using:
moles = mass / Mr

Hydrogen:
moles = 4 / 2 = 2

Oxygen:
10/32 = 0.3125

Therefore, it is evident that the moles of oxygen present, 0.3125, are less than those that are required for 2 moles of hydrogen, which is 1. This makes oxygen the limiting reactant, which is the one that limits the completion of a reaction.

I’d have to say no because without oxygen in the water the fish would all be dead. so if you want to fish for dead fish, pick the ponds with the lowest oxygen concentrations.

What are the choices?