To determine which of the given molecules or ions is the strongest reducing agent, we need to evaluate their tendencies to lose electrons. A strong reducing agent readily loses electrons and gets oxidized.
1. Magnesium ([tex]\(Mg\)[/tex]): Magnesium is a very strong reducing agent because it tends to lose its two valence electrons to form [tex]\(Mg^{2+}\)[/tex]. This makes it highly effective in reducing other substances.
2. Copper(I) ion ([tex]\(Cu^+\)[/tex]): This ion can act as a reducing agent, but it is not as strong as magnesium. [tex]\(Cu^+\)[/tex] can become [tex]\(Cu^{2+}\)[/tex] by losing one electron, but this is a less favorable process compared to [tex]\(Mg\)[/tex] losing two electrons.
3. Bromide ion ([tex]\(Br^-\)[/tex]): As an anion, [tex]\(Br^-\)[/tex] would typically act as an oxidizing agent by gaining electrons to form [tex]\(Br_2\)[/tex]. So, it is not a reducing agent in this context.
4. Silver(I) ion ([tex]\(Ag^+\)[/tex]): Similar to [tex]\(Cu^+\)[/tex], [tex]\(Ag^+\)[/tex] can act as a reducing agent by gaining electrons to form [tex]\(Ag\)[/tex], but it is less effective compared to metallic magnesium.
Given these choices, the molecule that acts as the strongest reducing agent is:
a. [tex]\(Mg\)[/tex]
Therefore, the correct answer is [tex]\(Mg\)[/tex], making option (a) the correct one, whereas option (e) ("None of these are strong reducing agents") is incorrect.
