What is the total number of moles of the reactants in the following reaction? 2h2(g) + o2(g) 2h2o(l)

Assuming that 2H2O(l) is the product, the reactants would be 2H2(g) and O2(g). The number of moles in the reactants would be 2 moles of H2 and 1 mole of O2.

What are the choices?

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na