The combustion of a compound CxHyOz yields CO2 + H2O; all of th carbon in the CO2 came from the compound, all of the hydrogen in the H2O came from the compound; and all of the oxygen in the H2O came from the compound. The oxygen in the CO2 came from the atmosphere.
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To understand why the oxygen in the CO2 came from the atmosphere, we need to analyze the given information about the combustion reaction of the compound CxHyOz.
When a compound undergoes combustion, it reacts with oxygen (O2) from the atmosphere to form carbon dioxide (CO2) and water (H2O). The key point to note is that the oxygen in the CO2 specifically comes from the atmosphere, not from within the compound.
Now, let's explore the composition of the compound CxHyOz further. We know that all of the carbon in the CO2 came from the compound, which means that the number of carbon atoms in the compound is equal to the number of carbon atoms in the CO2 produced. Let's call this number of carbon atoms "nC".
Similarly, all of the hydrogen in the water (H2O) came from the compound, which means that the number of hydrogen atoms in the compound is equal to the number of hydrogen atoms in the H2O produced. Let's call this number of hydrogen atoms "nH".
Lastly, all of the oxygen in the water (H2O) came from the compound, which means that the number of oxygen atoms in the compound is equal to the number of oxygen atoms in the H2O produced. Let's call this number of oxygen atoms "nO".
Based on this information, we can write the chemical formula of the compound as follows: CnC HnH OnOz.
To summarize:
- The compound CxHyOz consists of nC carbon atoms, nH hydrogen atoms, and nO oxygen atoms.
- When the compound is combusted, it reacts with oxygen from the atmosphere to form CO2 and H2O.
- The number of carbon atoms in the compound is equal to the number of carbon atoms in the CO2 produced (nC).
- The number of hydrogen atoms in the compound is equal to the number of hydrogen atoms in the H2O produced (nH).
- The number of oxygen atoms in the compound is equal to the number of oxygen atoms in the H2O produced (nO).
It's important to note that without knowing the specific values of nC, nH, and nO, we cannot determine the molecular formula of the compound CxHyOz. We can only deduce the relationships between the carbon, hydrogen, and oxygen atoms in the compound based on the given information.