Question

The incorrect statement among the following is : (1) beryllium oxide is amphoteric in nature (2) solubility of sulphates of second group elements decreases down the group (3) reducing power of hydride of alkali metal decreases down the group (4) Berylium has diagonal relationship with alumunium

Short answer

Statement (3) is incorrect.

Step-by-step solution

Analyze Each Statement

Carefully read through all given statements and identify key concepts related to the elements and groups in the periodic table.

Understand Amphoteric Nature

Statement (1) indicates that beryllium oxide is amphoteric, which means it can act as both an acid and a base. This is a correct property of beryllium oxide.

Examine Solubility Trend

Statement (2) mentions that the solubility of sulphates of second group elements decreases down the group. This is a true statement: solubility of sulphates, like MgSO4, CaSO4, etc., tends to decrease as you move down the alkaline earth metal group.

Evaluate Reducing Power of Hydrides

Statement (3) states that the reducing power of alkali metal hydrides decreases down the group. This is incorrect. In fact, the reducing power increases as you move down the group due to the larger atomic size and lower ionization energy.

Diagonal Relationship

Statement (4) says that beryllium has a diagonal relationship with aluminum. This is correct due to their similar properties in terms of charge/radius ratio and chemistry.

Identify the Incorrect Statement

From the analysis, the incorrect statement is: (3) reducing power of alkali metal hydrides decreases down the group.

Key concepts

periodic table trends

The periodic table is a powerful tool for understanding the elements and their behaviors. A few key trends can help us predict how elements will react and combine. For example, atomic size generally increases as you move down a group due to the addition of electron shells. Conversely, it decreases across a period from left to right as the increasing number of protons pulls electrons closer.

The table can also predict ionization energy, electronegativity, and metallic character. Ionization energy decreases as you go down a group and increases across a period. Electronegativity follows a similar trend. These trends are essential for understanding concepts like solubility, reactivity, and bond formation.

alkali metals and hydrides

Alkali metals like lithium, sodium, and potassium are highly reactive, especially with water. They form hydrides by combining with hydrogen. These hydrides have interesting characteristics. One crucial trend is that their reducing power increases as you move down the group. This is because larger atoms lose electrons more easily due to lower ionization energies.

Alkali metal hydrides (e.g., NaH, KH) are strong reducing agents, often used in chemical reactions to donate electrons. Understanding these trends helps predict reactions and product formation in various chemical processes.

solubility of sulphates

When looking at the alkaline earth metals (Group 2 elements), we can observe an interesting trend in the solubility of their sulphates. Sulphates of these metals become less soluble as you move down the group. For example, beryllium sulphate (BeSO4) is highly soluble in water, while barium sulphate (BaSO4) is virtually insoluble.

This pattern occurs because larger metal ions have lower lattice energies and more hydration energy. As a result, the ionic bonds between the metal cation and sulphate anion become weaker, decreasing solubility.

amphoteric oxides

Some oxides, like beryllium oxide (BeO), can act as either acids or bases. These are called amphoteric oxides. They react with both acids and bases to form salts and water. Amphoteric behavior is due to the oxide's ability to donate or accept electrons based on the reacting substance.

For beryllium oxide, it can react with hydrochloric acid to form beryllium chloride (BeCl2) and water, or it can react with sodium hydroxide to form sodium beryllate (Na2BeO2) and water. This dual behavior makes amphoteric oxides interesting and versatile in chemical reactions.