To determine which chemical equation has the same number of atoms in the reactants as in the products, we need to count the number of each type of atom on both sides of the equation.
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Zn + 2HCl → H2 + ZnCl2
- Reactants: Zn (1), H (2), Cl (2) → Total: 1 Zn + 2 H + 2 Cl = 5 atoms
- Products: H (2), Zn (1), Cl (2) → Total: 1 Zn + 2 H + 2 Cl = 5 atoms
- Atoms are balanced.
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CH4 + O2 → CO2 + 2H2O
- Reactants: C (1), H (4), O (2) → Total: 1 C + 4 H + 2 O = 7 atoms
- Products: C (1), H (4), O (4) → Total: 1 C + 4 H + 4 O = 9 atoms
- Atoms are not balanced.
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CO2 + H2O → CH2OH + O2
- Reactants: C (1), O (3), H (2) → Total: 1 C + 3 O + 2 H = 6 atoms
- Products: C (1), O (3), H (2) → Total: 1 C + 3 O + 2 H = 6 atoms
- Atoms are balanced.
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Li2CO3 → LiO + CO2
- Reactants: Li (2), C (1), O (3) → Total: 2 Li + 1 C + 3 O = 6 atoms
- Products: Li (1), O (1), C (1), O (2) → Total: 1 Li + 2 O + 1 C = 4 atoms
- Atoms are not balanced.
Based on the above analysis, the equations where the number of atoms in the reactants is the same as the number of atoms in the products are:
- Zn + 2HCl → H2 + ZnCl2
- CO2 + H2O → CH2OH + O2
If you need to choose one correct answer from the provided options, the first equation is commonly used in basic chemistry contexts for demonstrating balanced reactions.