To balance the equation where you change to 3 molecules of \( H_2 \), you get:
\[ 3H_2 + 1.5O_2 \rightarrow 3H_2O \]
However, since we typically want whole numbers in a balanced chemical equation, we can multiply everything by 2 to eliminate the fraction:
\[ 6H_2 + 3O_2 \rightarrow 6H_2O \]
From this balanced equation, we can draw conclusions:
- You produce 6 molecules of water from 6 molecules of hydrogen and 3 molecules of oxygen.
- There are no leftover molecules since all the reactants are used up.
Now, let's evaluate the given statements:
- The equation will produce three molecules of water. (Incorrect, it produces 6 molecules of water.)
- The result of the equation will be the same. (Incorrect, the amount of water produced is different.)
- It is not possible to produce water without leftover molecules. (Incorrect, it is possible as shown in the balanced equation.)
- Each oxygen molecule will combine with 2 hydrogen molecules with no leftover molecules. (Correct, as each \( O_2 \) combines with 4 \( H_2 \) to produce 4 molecules of \( H_2O \) in the balanced equation.)
Thus, the correct statement is:
Each oxygen molecule will combine with 2 hydrogen molecules with no leftover molecules.