Question

In a hydrogen fuel cell, hydrogen gas and oxygen gas are combined to form water. write the balanced chemical equation describing this reaction (using lowest whole-number coefficients.

Answer 1

I believe it is this:
2 H2 + O2 ---> 2 H2O

Answer 2

Answer:

2H₂ + O₂ → 2H₂O

Explanation:

The problem tells us that hydrogen gas (H₂) and oxygen gas (O₂) are the reactants, while water (H₂O) is the only product. Thus, the reaction is:

H₂ + O₂ → H₂O

In order to balance this equation, we begin with counting the atoms of O present in the left side and in the right side of the equation. Because there are two O atoms in the left but only one on the right, we add a coefficient of 2 in the right side:

H₂ + O₂ → 2H₂O

Now we count the H atoms, there are 2 in the left and 4 in the right, so we add a coefficient of 2 for the hydrogen gas:

2H₂ + O₂ → 2H₂O

Now there are 4 H atoms in both sides, and 2 O atoms in both sides, so the equation is balanced.