When the following equation is balanced with the lowest whole number coefficients possible, what is the coefficient in front of Na?

Na (s) + H2O (g) yields NaOH (aq) + H2 (g)

1

2

3

4

The unbalanced chemical reaction is

Na (s) + H2O (g) yields NaOH (aq) + H2 (g)

By inspection,

There is 1 mole of Na in both sides

There is 2 moles of H in the left and 3 moles in the right side.

There is 1 mole of O in both sides

We balance the reaction by:

2Na (s) + 2H2O (g) yields 2NaOH (aq) + H2 (g)

The answer is 2