Question

Which of the following statements are not correct? i) \( \text{BeO has rock-salt structure} \)
ii) \( \text{BeSO}_4 \text{ is readily soluble in water} \)
iii) \( \text{The maximum coordination number of beryllium is four} \)
iv) \( \text{Be(OH)}_2 \text{ is basic in nature} \)

• A. ii, iii only
• B. ii, iii, iv
• C. i, iv only
• D. iii, iv only

Hint:

- BeO forms a rock-salt structure, which is typical for many oxides. - Beryllium sulfate (BeSO\(_4\)) is not highly soluble in water, unlike other alkali and alkaline earth metal sulfates. - Beryllium exhibits a coordination number of 6 due to its smaller ionic radius and high charge density.

Answer 1

The Correct Option is B

Step 1: Let's analyze the statements:

Option (A) BeO indeed has a rock-salt structure, so statement i is correct. 

Option (B) BeSO\(_4\) is actually poorly soluble in water, so statement ii is incorrect. 

Option (C) The maximum coordination number of beryllium is 6, not 4, so statement iii is incorrect. 

Option (D) Be(OH)\(_2\) is basic in nature, which is true, so statement iv is correct. 

Thus, the incorrect statements are ii, iii, and iv. Therefore, the correct answer is option (2).