Question

The following observations were made concerning metals \(A, B, C\), and \(D\). (a) When a strip of metal \(\mathrm{A}\) is placed in a solution of \(\mathrm{B}^{2+}\) aons, no reaction is observed. (b) Similarly, \(A\) in a solution containing \(\mathrm{C}^{+}\)ions produces no reaction. (c) When a strip of metal \(D\) is placed in a solut?on of " \(\mathrm{C}^{+}\)àns, black metallic C deposits on the surface of D, and the solution tests posatively for \(\mathrm{D}^{2+}\) tons. (d) When a piece of metallic B is placed in a solution of \(D^{2+}\) ions, metallic \(D\) appears on the surface of \(\mathrm{B}\) and \(\mathrm{B}^{2+}\) jons are found in the solution. Arrange the ions \(\mathrm{A}^{4}, \mathrm{~B}^{2+}, \mathrm{C}^{4}\), and \(\mathrm{D}^{24}\) in order of their ability to attract clectrons. List them in order of increasing ability.

Short answer

A < C < B < D.

Step-by-step solution

Identify Reaction Observations

Analyze the given observations for metals A, B, C, and D in different ion solutions. Note down which metals react with which ions.

Observation Analysis for Metals A and B

From the observations: (a) Metal A in B^(2+) shows no reaction. (d) Metal B in D^(2+) shows metallic D appearing on B's surface, and B^(2+) found in solution. This indicates B donates electrons to D^(2+), forming D and B^(2+). Hence, D is more able to attract electrons than B.

Observation Analysis for Metals A and C

From the observations: (b) Metal A in C^(+) shows no reaction. (c) Metal D in C^(+) produces metallic C on D with D^(2+) in solution. This indicates D is more able to attract electrons than C.

Determine Reactivity Order Based on Data

Summarize the reactivity order: 1. Between B and D, D attracts electrons more.2. Between A and B, B attracts electrons more.3. Between A and C, C attracts electrons more.

Order of Reactivity

Arrange the ions in order of increasing ability to attract electrons based on their reactivity: A < C < B < D.

Key concepts

Electrochemistry

Electrochemistry is the branch of chemistry that deals with the relationship between electrical energy and chemical reactions. It is crucial for understanding how batteries, fuel cells, and electrolysis work. In the context of the exercise, when different metals are placed in solutions containing ions, we observe various reactions based on the electrochemical series. The electrochemical series helps us predict which metals will act as better reducing agents, or in simpler terms, which metal will give up electrons more easily to reduce another substance.
In this exercise, we see that when metals like D and B are placed in different ionic solutions, they either react and form deposits or do not react at all. This indicates their position in the electrochemical series. A metal that easily gives up electrons will react, whereas a metal lower in the series might not react when combined with ions of a metal higher in the series.

Redox Reactions

Redox (reduction-oxidation) reactions are reactions where one substance loses electrons (oxidation) and another substance gains electrons (reduction). These reactions are fundamental to electrochemistry.
In the provided exercise, a series of redox reactions are analyzed. For instance:

• When metal D is placed in a solution of C⁺ ions, black metallic C deposits on the surface of D while D²⁺ ions are found in the solution. This indicates that D loses electrons (oxidized) and C gains electrons (reduced).
• Similarly, when metal B is placed in a solution of D²⁺ ions, metallic D appears on the surface of B, and B²⁺ ions are found in the solution. Here, B loses electrons (oxidized) and D gains electrons (reduced).

These reactions help us determine the order of reactivity of the metals based on their ability to attract or donate electrons.

Metal Reactivity

Metal reactivity refers to the ability of a metal to participate in chemical reactions, especially those involving the transfer of electrons. The reactivity series of metals arranges metals in order of decreasing reactivity. This series helps predict how metals will react with other substances.
In the exercise, different metals (A, B, C, and D) show varying reactions when placed in ion solutions:

• No reaction occurs when metal A is placed in solutions containing B²⁺ and C⁺ ions. This indicates that A is less reactive compared to both B and C.
• Metal D reacts with C⁺ ions, forming metallic C and D²⁺ ions. Thus, D is more reactive than C.
• Metal B reacts with D²⁺ ions, forming metallic D and B²⁺ ions, indicating that D is more reactive than B.

Based on these observations, we can order the metals in increasing reactivity: A < C < B < D.