If you were to have a lewis dot structure, such as, C2H5OH, where is the O placed?
Between a carbon and an H.
The Lewis dot structure is a diagram that represents the arrangement of atoms and valence electrons in a molecule. In the case of C2H5OH (ethanol), we need to determine the placement of the oxygen atom (O).
To find the placement of the oxygen atom, we first need to count the total number of valence electrons for the molecule. Carbon (C) has 4 valence electrons, hydrogen (H) has 1, and oxygen (O) has 6. Since there are two carbon atoms, we multiply the valence electrons of carbon by 2. Additionally, there are six hydrogen atoms (H), so we multiply the valence electrons of hydrogen by 6. Finally, adding the valence electrons of oxygen, carbon, and hydrogen together gives us the total number of valence electrons.
C (4) x 2 + H (1) x 6 + O (6) = 8 + 6 + 6 = 20 valence electrons
Next, we start by placing the atoms in a way that satisfies the octet rule, which states that atoms tend to gain, lose, or share electrons to achieve a full outer electron shell of 8 electrons (except hydrogen, which can have a maximum of 2 electrons in its outer shell).
Since carbon forms a total of four bonds, we can place the carbon atoms in the middle and connect them with a double bond. This arrangement satisfies carbon's need for four additional electrons to complete its octet.
H H
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C = C
Next, we add hydrogen atoms around the carbon atoms, as each hydrogen can form one bond with carbon.
H H
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C = C
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H H
Finally, with the remaining valence electrons, we place them around the oxygen atom. Oxygen needs two additional electrons to complete its octet. Since it has six valence electrons, we place them around the oxygen atom in pairs (each pair represents a shared electron pair).
H H
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C = C
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H O H
As we can see, the oxygen atom is placed between a carbon atom and two hydrogen atoms in the molecule C2H5OH (ethanol).