Problem 92 - Chemistry: Principles and Reactions

Question

Consider three metals, \(\mathrm{X}, \mathrm{Y}\), and \(\mathrm{Z}\), and their salts, \(\mathrm{XA}, \mathrm{YA}\), and \(\mathrm{ZA}\). Three experiments take place with the following results: \- \(\mathrm{X}+\mathrm{hot} \mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{H}_{2}\) bubbles \(\mathrm{X}+\mathrm{YA} \longrightarrow\) no reaction I \(\mathrm{X}+\mathrm{ZA} \longrightarrow \mathrm{X}\) discolored \(+\mathrm{Z}\) Rank metals \(\mathrm{X}, \mathrm{Y}\), and \(\mathrm{Z}\), in order of decreasing strength as reducing agents.

Step-by-Step Solution

Answer

Question: Rank the metals X, Y, and Z in order of decreasing strength as reducing agents based on the given information from three experiments. Answer: X > Z > Y

Step 1: Analyzing the given information from three experiments

In the first experiment, X reacts with hot water to produce hydrogen bubbles. This tells us that X is a reactive metal, as it displaces hydrogen from water. In the second experiment, X does not react with YA, which suggests that X is less reactive than Y, as it cannot displace Y from its salt. In the third experiment, X reacts with ZA and forms X discolored and Z. This implies that X can displace Z from its salt and thus X is more reactive than Z.

Step 2: Ranking the metals according to their reactivity#advice_likelihood#0.8advice_end

Based on the above analysis, the order of decreasing reactivity (or reducing strength) is: - X is more reactive than Y, so Y is the weakest reducing agent. - X is more reactive than Z, so X is the strongest reducing agent. - Z is in the middle, so Z is the intermediate reducing agent. Thus, the order of decreasing strength as reducing agents is X > Z > Y.

Key Concepts

Chemical Reactivity

Chemical reactivity refers to the tendency of a substance to engage in chemical reactions. In the context of metals, reactivity can vary significantly across the periodic table. Highly reactive metals, such as those in the alkali and alkaline earth metal groups, can readily lose electrons to form positive ions. This property defines how a metal will react with substances like water, acids, and the components of salts.

Understanding the reactivity series is crucial for predicting outcomes of reactions. Metals higher in the series can displace those lower down from their compounds. In our exercise, the reactivity series helped determine that Metal X was able to displace hydrogen from water, indicating its high reactivity, while its failure to react with compound YA suggested it was less reactive than Metal Y.

Displacement Reactions

Displacement reactions are a type of chemical reaction where a more reactive element displaces a less reactive one from its compound. In the exercise, Metal X can replace Hydrogen in water, and displace Metal Z from ZA, but it cannot displace Metal Y from YA.

Through these observations, the reactivity ordering can be deduced. Displacement is a powerful tool in chemistry for extracting metals from their ores and in industrial applications where certain metals are purified by displacing them with others. These reactions are predictive when you know the reactivity series and are pivotal in understanding why certain metals are more suitable as reducing agents.

Reducing Agents

Reducing agents, or reducers, are substances that can donate electrons to other substances during a chemical reaction. Metals often serve as reducing agents due to their ability to lose electrons easily.

In redox reactions, the strength of a reducing agent is indicated by its willingness to lose electrons. Metals that lose electrons easily are considered good reducing agents. The exercise demonstrated that Metal X was the strongest reducing agent among the three because it could easily donate electrons to both hot water and Metal Z's salt. However, since it could not react with Metal Y's salt, it inferred that Metal Y was an even stronger reducing agent. This quality is fundamental in processes like electroplating, battery design, and metallurgy.