In chloroform, \(\mathrm{CHCl}_{3}\) (a) Assign an oxidation state to each atom in the molecule. (Hint: Draw a dot diagram first.) (b) How many electrons does the \(\mathrm{C}\) atom own by oxidation-state electron bookkeeping? (c) How many more or fewer valence electrons are assigned to the \(\mathrm{C}\) atom here than are present in a free \(C\) atom? (d) Is it correct or incorrect to say that the \(\mathrm{C}\) atom in \(\mathrm{CHCl}_{3}\) has a complete octet of valence electrons? Explain.

For each atom, we'll first draw a dot diagram based on its bonds to other atoms and then use these diagrams to deduce the oxidation states. Remember that Hydrogen has 1 valence electron, Carbon has 4 valence electrons, and Chlorine has 7 valence electrons. In CHCl3, Carbon is bonded to 1 Hydrogen and 3 Chlorine atoms. To determine the oxidation states, we'll assign electrons according to their electronegativity followed by the rules of calculating the oxidation state for each atom. - Hydrogen has an oxidation state of +1. - Carbon is less electronegative than Chlorine, so Chlorine will have a negative oxidation state. Since there are 3 Chlorine atoms, they will each have an oxidation state of -1. - Sum of oxidation states in a molecule should equal to 0, so in this case: \(x + 1 - 1 - 1 - 1 = 0\) Solving for x, we get x = 2. So, Carbon has an oxidation state of +2.

To calculate the number of owned electrons by the Carbon atom using oxidation-state bookkeeping, we'll subtract the number of valence electrons in the free atom from the oxidation state we determined (Carbon has 4 valence electrons in a free atom). Owned electrons = Valence electrons in a free atom - Oxidation state Owned electrons = 4 - 2 Owned electrons = 2 The Carbon atom owns 2 electrons by oxidation-state electron bookkeeping.

We have already determined the owned electrons by the Carbon atom in CHCl3 (which is 2). A free Carbon atom has 4 valence electrons. Now, we will determine the difference between these two values. Difference in valence electrons = Valence electrons in CHCl3 - Valence electrons in a free Carbon atom Difference in valence electrons = 2 - 4 Difference in valence electrons = -2 So, in CHCl3, the Carbon atom has 2 fewer valence electrons than it does in its free state.

In CHCl3, Carbon is bonded to 1 Hydrogen and 3 Chlorine atoms. According to the octet rule, an atom is considered to have a complete octet when it is surrounded by 8 electrons in its outer shell. In chloroform, the Carbon atom is sharing 1 electron from Hydrogen and 3 electrons from the Chlorine atoms, which is a total of 4 shared electrons. Additionally, the Carbon atom already has 2 own valence electrons, as we previously calculated. Total owned and shared electrons by Carbon in CHCl3 = Shared electrons + Owned electrons Total owned and shared electrons = 4 (shared) + 2 (owned) So, the Carbon atom in CHCl3 has a total of 6 electrons in its outer shell (not 8), which means that it does not have a complete octet of valence electrons.