To determine which chemical equation has the same number of atoms in the reactants and products, we can count the number of each type of atom on both sides of the equation.
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CH4 + O2 → CO2 + 2H2O
- Reactants: 1 C, 4 H, 2 O → 1 C, 4 H, 2 O = 7 atoms total
- Products: 1 C, 4 H, 2 O → 1 C, 4 H, 2 O = 7 atoms total
(This equation is balanced.)
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Zn + 2HCl → H2 + ZnCl2
- Reactants: 1 Zn, 2 Cl, 2 H → 1 Zn, 2 Cl, 2 H = 5 atoms total
- Products: 1 Zn, 2 Cl, 2 H → 1 Zn, 2 Cl, 2 H = 5 atoms total
(This equation is balanced.)
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Li2CO3 → LiO + CO2
- Reactants: 2 Li, 1 C, 3 O → 2 Li, 1 C, 3 O = 6 atoms total
- Products: 2 Li, 1 C, 2 O → 2 Li, 1 C, 2 O = 5 atoms total
(This equation is not balanced.)
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CO2 + H2O → CH2OH + O2
- Reactants: 1 C, 2 O, 2 H → 1 C, 2 O, 2 H = 5 atoms total
- Products: 1 C, 2 H, 2 O → 1 C, 2 H, 2 O = 5 atoms total
(This equation is balanced.)
Conclusion: The equations that have the same number of atoms in the reactants and products are:
- CH4 + O2 → CO2 + 2H2O (Balanced)
- Zn + 2HCl → H2 + ZnCl2 (Balanced)
- CO2 + H2O → CH2OH + O2 (Balanced)
Given the options, the correct responses that meet the criteria are the first, second, and last equations.