Burning 2 mol of ethane in oxygen yielded 4 mol of carbon monoxide (IV). Doesn’t this fact contradict the law of conservation of mass of substances during chemical reactions?
2C2H6 + 7O2 = 4CO2 + 6H2O.
As can be seen from the reaction equation, for 2 mol of ethane entering into the interaction, 4 mol of carbon dioxide is obtained. So the statement in the task does not contradict the law of conservation of mass.
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