Question

Which among the following is kinetically inert towards water? (a) \(\mathrm{Na}\) (b) Be (c) \(\mathrm{Ca}\) (d) \(\mathbf{K}\)

Short answer

Be (Beryllium) is kinetically inert towards water.

Step-by-step solution

Understanding kinetic inertness

Kinetically inert substances are those that do not readily react. In the context of water, it means the substance will not react quickly or at all with water.

Evaluate the reactivity of elements with water

Sodium (Na), Calcium (Ca), and Potassium (K) are all highly reactive with water, reacting swiftly and often violently. Beryllium (Be), on the other hand, does not react with water due to its strong oxide layer that inhibits reaction at room temperature.

Determining the correct option

Based on the reactivity series and properties of the elements, Be (Beryllium) is kinetically inert towards water compared to the other provided elements.

Key concepts

Reactivity of Elements with Water

Understanding how different elements react with water is crucial for comprehending various chemical behaviors. Reactivity with water varies broadly among elements, often resulting in the release of gases or forming hydroxides. For instance, when highly reactive alkali metals like Sodium (a) and Potassium (K) come into contact with water, they engage in vigorous reactions, producing hydrogen gas and the corresponding alkali hydroxides, which are strongly alkaline. On the contrary, some elements, like Beryllium (Be), are noted for their resilience to react with water, a phenomenon attributed to their protective oxide layer. This layer acts as a shield, preventing water molecules from reaching the metal's surface, which keeps Beryllium kinetically inert under normal conditions.

In educational terms, it's helpful to compare this to a situation many students are familiar with: Having a waterproof jacket. Just as the jacket prevents you from getting wet in rain, Beryllium's oxide layer shields it from reacting with water. Moreover, understanding these interactions can inform us about the behavior of elements in biological systems, industrial processes, and even in our everyday lives.

Reactivity Series

The reactivity series is an empirical arrangement of metals, listed by their reactivity from highest to lowest. It is a predictive tool used to assess the outcome of displacement reactions as well as to predict which metals will react with acids or water and what products they will form. The series starts with highly reactive elements like Potassium and Sodium at the top, descending to include less reactive elements such as Beryllium towards the bottom.

Imagine the reactivity series as a leaderboard in a video game, where the top players are the most explosive and the ones at the bottom are the least likely to cause a stir. In our case, elements like Sodium (a) and Potassium (K) are the top scorers because they 'play' intensely with water, rapidly changing the game by releasing energy and products like hydrogen gas. But Beryllium (Be), similar to a player who rarely makes moves, remains at the lower ranks, as it prefers stability and is less inclined to react.

Chemical Properties of Elements

The chemical properties of elements are the characteristics that define how they react under different conditions. These properties are influenced by factors such as electronic configuration, atomic size, and the presence of an oxide layer. For example, Beryllium (Be), with its stable electron configuration and small atomic size, tends to form a protective oxide layer, whereas elements like Sodium (a) and Potassium (K), with larger atoms and a more reactive electron configuration, do not form such a protective layer and are thus more reactive with water.

To explain this in simpler terms, imagine each element as a person with unique behavior patterns. Some people (like Sodium and Potassium) are spontaneous and react quickly to stimuli, while others (like Beryllium) are more reserved and take a protective stance. In the world of chemistry, these behaviors translate into whether an element is likely to engage in a reaction or remain isolated from the action. It's like knowing whether a friend would enjoy a surprise party (reactive) or prefer a quiet evening at home (inert).