Question

1. what number should precede (be in front) h₂ in the chemical equation below in order for the equation to be balanced?

h₂ + o₂ → 2h₂o

Explanation:

Step1: Count atoms on both sides

On the right - hand side (RHS) of the equation \(2H_2O\), the number of hydrogen (\(H\)) atoms is \(2\times2 = 4\) and the number of oxygen (\(O\)) atoms is \(2\). On the left - hand side (LHS) of the equation \(H_2+O_2\), the number of oxygen atoms is \(2\) (from \(O_2\)) and the number of hydrogen atoms is \(2\) (from \(H_2\)).

Step2: Balance hydrogen atoms

To balance the hydrogen atoms, we need \(2\) molecules of \(H_2\) on the LHS. The balanced chemical equation is \(2H_2 + O_2=2H_2O\)

Answer:

\(2\)