Question

All the Group \(1 \mathrm{~A}\) and \(2 \mathrm{~A}\) metals are produced by electrolysis of molten salts. Why?

Short answer

Group 1A and 2A metals are produced by electrolysis of molten salts because this method allows for effective and controlled extraction of these reactive metals from their stable, ionic compounds. Electrolysis enables a clean and efficient reduction process, yielding pure metal, which is difficult to achieve through traditional reduction processes due to the high reactivity of these metals. Moreover, these metals have relatively low melting points, which makes it easier to obtain their molten salts for the process, thus making electrolysis more effective compared to electrolysis of solid salts or aqueous solutions.

Step-by-step solution

Understanding Group 1A and 2A Metals

Group 1A metals, also known as alkali metals, include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Group 2A metals, called alkaline earth metals, comprise beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). These metals are quite reactive, specifically with elements like oxygen, so they are rarely found in their pure form in nature. Instead, they form ionic compounds known as salts, which are more stable.

Understanding Electrolysis

Electrolysis is a process used to split ionic compounds into their constituent elements using an electric current. In this case, we will be focusing on the electrolysis of molten salts. During the process, positive metal ions (cations) migrate towards the negatively charged electrode (cathode), while negative ions (anions) migrate towards the positively charged electrode (anode). The metal ions gain electrons at the cathode and are reduced to the pure metal. Meanwhile, the anions lose electrons at the anode and are oxidized, often to a gas like oxygen or chlorine.

Why Electrolysis of Molten Salts is Used

Group 1A and 2A metals are produced by electrolysis of molten salts because it is a suitable method to extract reactive metals from their stable, ionic compounds. The high reactivity of these metals makes it challenging to isolate them using common reduction processes like heating with carbon, which can lead to further reactions and impurities. On the other hand, electrolysis allows for a cleaner and more controlled reduction process, yielding the pure metal. When the salts are melted, the ions become mobile and can move towards their respective electrodes, making electrolysis more effective compared to electrolysis of solid salts or aqueous solutions. Additionally, these metals have relatively low melting points, which makes it easier to obtain their molten salts for this process. In summary, the production of Group 1A and 2A metals through electrolysis of molten salts is preferred because it allows for effective and controlled extraction of these reactive metals from their stable, ionic compounds in a relatively clean and efficient manner.