To determine which chemical equation has the same number of atoms in the reactants and products, let's analyze both equations:
A. CO2 + H2O -- CH2OH + O2
-
Reactants:
- CO2: 1 carbon (C), 2 oxygens (O)
- H2O: 2 hydrogens (H), 1 oxygen (O)
- Total: 1 C, 3 O, 2 H (6 atoms total)
-
Products:
- CH2OH: 1 carbon (C), 4 hydrogens (H), 1 oxygen (O)
- O2: 2 oxygens (O)
- Total: 1 C, 3 O, 4 H (8 atoms total)
The number of atoms in reactants (6) is not equal to the number of atoms in products (8).
C. Zn + 2HCl -- H2 + ZnCl2
-
Reactants:
- Zn: 1 zinc (Zn)
- 2HCl: 2 hydrogens (H), 2 chlorines (Cl)
- Total: 1 Zn, 2 H, 2 Cl (5 atoms total)
-
Products:
- H2: 2 hydrogens (H)
- ZnCl2: 1 zinc (Zn), 2 chlorines (Cl)
- Total: 1 Zn, 2 H, 2 Cl (5 atoms total)
The number of atoms in reactants (5) is equal to the number of atoms in products (5).
Thus, the correct answer is:
C. Zn + 2HCl -- H2 + ZnCl2