Which equation represents a single replacement reaction that can occur? F2 + 2NaCl ? 2NaF + Cl2 Cl2 + 2NaF ? 2NaCl + F2 Zn + 2NaF ? ZnF2 + 2Na Cu + 2NaCl ? CuCl2 + 2Na
The Correct Answer and Explanation is:
The correct equation is:
F₂ + 2NaCl → 2NaF + Cl₂
This reaction is an example of a single replacement reaction. In this type of reaction one element in its pure form replaces another element in a compound. Here the free element is fluorine (F₂), and it is capable of displacing chlorine from sodium chloride (NaCl). In a single replacement process the activity or reactivity of the elements involved plays an essential role. The halogens, which include fluorine and chlorine, follow a specific order of reactivity. Fluorine is positioned at the top of the halogen reactivity series. This high reactivity means that fluorine has a strong ability to gain electrons and bind with sodium, forming sodium fluoride (NaF). The chlorine that was previously in sodium chloride is expelled as chlorine gas (Cl₂).
The concept behind this reaction relies on the principle that a more reactive element can displace a less reactive element from its compound. In this instance, because fluorine is more reactive than chlorine, it replaces chlorine when it comes in contact with sodium chloride. When F₂ reacts with NaCl two fluoride ions replace two chloride ions from the sodium chloride lattice. The resulting products are sodium fluoride, which is a stable ionic compound, and elemental chlorine gas, which forms as a diatomic molecule.
It is important to compare this reaction with the other options provided. The second equation, Cl₂ with NaF, would be unfavorable because chlorine does not have the ability to displace the stronger oxidizing fluorine from its compound. The third equation proposes that zinc replaces sodium, but zinc is lower than sodium in the metal reactivity series. Similarly, the fourth equation suggests that copper can replace sodium, which is not possible due to copper being less reactive than sodium. Therefore, among the four options, only the reaction involving fluorine and sodium chloride represents a feasible single replacement reaction.
