To determine what is known about the reactants in a chemical reaction that produces carbon dioxide ([tex]\(CO_2\)[/tex]) and water ([tex]\(H_2O\)[/tex]), let's consider the balanced chemical equation and the elements involved.
The reaction in question produces:
- Carbon dioxide ([tex]\(CO_2\)[/tex])
- Water ([tex]\(H_2O\)[/tex])
From this information, we know the products contain the following atoms:
- Carbon (C) from [tex]\(CO_2\)[/tex]
- Oxygen (O) from both [tex]\(CO_2\)[/tex] and [tex]\(H_2O\)[/tex]
- Hydrogen (H) from [tex]\(H_2O\)[/tex]
In a chemical reaction, the atoms in the reactants are rearranged to form the products, but the types of atoms present must be the same on both sides of the reaction equation. Therefore, the reactants must contain some combination of the atoms C, O, and H.
Let's examine each of the given answer choices:
A. The reactants are also [tex]\(CO_2\)[/tex] and [tex]\(H_2O\)[/tex].
- This is not necessarily true. While [tex]\(CO_2\)[/tex] and [tex]\(H_2O\)[/tex] are the products, it does not mean they must also be the reactants. The initial substances could be different compounds containing C, O, and H atoms.
B. The reactants do not include any C, O, or H atoms.
- This is incorrect because the products contain C, O, and H atoms, and therefore, the reactants must contain these atoms as well.
C. The reactants include [tex]\(CO_2\)[/tex] and [tex]\(H_2O\)[/tex].
- Similar to choice A, this is not necessarily true. The reactants could be other substances that contain C, O, and H atoms, which upon reacting produce [tex]\(CO_2\)[/tex] and [tex]\(H_2O\)[/tex].
D. The reactants include substances with only C, O, and H atoms.
- This is correct. Because the products are [tex]\(CO_2\)[/tex] and [tex]\(H_2O\)[/tex] containing C, O, and H atoms, the reactants must also have been composed of these same atoms. There cannot be any other types of atoms present because no other types of atoms appear in the products.
Thus, the correct answer is:
D. The reactants include substances with only C, O, and H atoms.
