Questions: Which equation represents the first electron affinity of a chlorine atom? Cl^+(g) + e^- -> Cl(g) Cl^-(g) -> Cl(g) + e^- Cl(g) -> Cl^+(g) + e^- Cl(g) + e^- -> Cl^-(g)

Solution Steps

Electron affinity is the energy change that occurs when an electron is added to a neutral atom in the gas phase to form a negative ion.

We need to identify which equation represents the addition of an electron to a neutral chlorine atom (\(\mathrm{Cl}(\mathrm{g})\)) to form a chloride ion (\(\mathrm{Cl}^{-}(\mathrm{g})\)).

• The first equation: \(\mathrm{Cl}^{+}(\mathrm{g})+\mathrm{e}^{-} \rightarrow \mathrm{Cl}(\mathrm{g})\) involves a positively charged chlorine ion gaining an electron to become neutral.
• The second equation: \(\mathrm{Cl}^{-}(\mathrm{g}) \rightarrow \mathrm{Cl}(\mathrm{g})+\mathrm{e}^{-}\) involves a negatively charged chlorine ion losing an electron to become neutral.
• The third equation: \(\mathrm{Cl}(\mathrm{g}) \rightarrow \mathrm{Cl}^{+}(\mathrm{g})+\mathrm{e}^{-}\) involves a neutral chlorine atom losing an electron to become positively charged.
• The fourth equation: \(\mathrm{Cl}(\mathrm{g})+\mathrm{e}^{-} \rightarrow \mathrm{Cl}^{-}(\mathrm{g})\) involves a neutral chlorine atom gaining an electron to become negatively charged.

Final Answer