Question

\(\mathrm{Mg}\) and \(\mathrm{Zn}\) have following resemblance: (a) Both of them can be used as electrodes (b) \(\mathrm{MgO}\) and \(\mathrm{ZnO}\) are amphoteric. (c) Both of them can be used to prevent corrosion (d) \(\mathrm{MgCO}_{3}, \mathrm{ZnCO}_{3}\) both on heating give their oxides.

Short answer

(a), (c), and (d) are correct.

Step-by-step solution

Identify Characteristics

First, identify the key characteristics mentioned in the options. (a) Both Mg (Magnesium) and Zn (Zinc) can be used as electrodes. (b) Compare the nature of MgO and ZnO in terms of amphoterism (their ability to react with both acids and bases). (c) Both Mg and Zn are used in preventing corrosion, such as in galvanization or sacrificing coatings to protect other metals. (d) Examine if heating  MgCO₃ and ZnCO₃ results in the release of CO₂, leaving behind their respective metal oxides.

Analyze Each Statement

Step through each statement to determine accuracy. (a) True: Both Mg and Zn can be used as electrodes in galvanic cells and electrolysis processes. (b) False: ZnO is amphoteric (reacts with both acids and bases), but MgO is basic and reacts mainly with acids. (c) True: Both metals help prevent corrosion, e.g., Zn is widely used in galvanizing iron. (d) True: Both MgCO₃ and ZnCO₃ decompose upon heating to form their oxides and release CO₂, hence act similarly upon heating.

Determine Correct Options

Now, determine which statements are correct based on the analysis: Statements (a), (c), and (d) are correct. Therefore Mg and Zn resemble each other in terms of their use as electrodes, their role in preventing corrosion, and their similar behavior when heated as carbonates.

Key concepts

Electrodes

In the realm of electrochemistry, electrodes play a crucial role. Electrodes are conductive materials that allow the transfer of electrons into or out of a chemical system. In the context of magnesium (Mg) and zinc (Zn), both these elements can act as electrodes in various applications like galvanic cells and electrolysis processes.

• Galvanic cells use Mg or Zn as electrodes to convert chemical energy into electrical energy. Here, these metals often lose electrons, undergoing oxidation and contributing to the overall cell reaction.
• In electrolysis, these metals can either gain or lose electrons based on their placement within the system, facilitating various reactions including metal purification.

These applications underscore the versatility of Mg and Zn as both active participants in energy generation and in promoting reactions necessary for industrial processes.

Amphoteric Oxides

Amphoteric oxides are oxides that can react both with acids and bases. This unique property allows them to behave differently under varying chemical conditions. In the context of the exercise, while zinc oxide ( ZnO) showcases amphoterism, magnesium oxide (MgO) does not, as it predominantly acts as a basic oxide.

• ZnO, as an amphoteric oxide, reacts seamlessly with acids to form salts and water, and with bases to form complex compounds such as zincates.
• MgO, on the other hand, primarily interacts with acids, forming magnesium salts and plays a limited role with bases.

Understanding the nature of these oxides is vital in predicting their behavior in chemical reactions, especially when considering them for industrial applications that involve neutralization or complex compound formation.

Corrosion Prevention

Preventing corrosion is a key consideration in material science, and both Mg and Zn are often employed for this purpose. Corrosion can drastically reduce the lifespan of metals and structures, costing significant resources and efforts in replacements and repairs.

• Zinc is prominently used in the process of galvanization, where it coats iron or steel components to prevent rusting. This sacrificial action effectively protects the underlying metal by preferentially undergoing oxidation.
• Magnesium, while not as popular as zinc, is used in specific applications like storage tanks and pipelines, where it acts as a sacrificial anode, similarly protecting the metals from oxidative damage.

By employing these metals, industries can extend the durability and service life of metal structures, providing both economic and systemic advantages.

Decomposition of Metal Carbonates

The decomposition of metal carbonates, such as magnesium carbonate ( MgCO_3) and zinc carbonate ( ZnCO_3), is an important reaction in the field of chemistry. This process typically involves the application of heat to break down the carbonate compounds.

• When heated, both MgCO_3 and ZnCO_3 decompose to form their respective metal oxides, along with the release of carbon dioxide (CO_2).
• This reaction is significant for producing metal oxides, which are valuable intermediates in various industrial processes, including the manufacturing of certain materials and chemicals.

Understanding this decomposition process is critical in industrial operations involving heat where carbonate compounds serve as essential raw materials, influencing production strategies and costs.