某物质R与氧气反应的化学方程式为R+2O2 点燃__ CO2+2H2O，则R的化学式是_1推断R化学式的依据是_2。_刷题宝

题干

某物质R与氧气反应的化学方程式为R+2O₂ 点燃__ CO₂+2H₂O，则R的化学式是____推断R化学式的依据是____。

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答案(点此获取答案解析）

CH₄,化学反应前后原子的种类、数目没有改变

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