Question

Among the following, the correct statements are:

• A. I, III only
• B. II, IV only
• C. I, IV only
• D. III, IV only

Hint:

Saline hydrides are generally non-volatile due to strong ionic bonding. Electron-precise hydrides do not act as Lewis bases because they lack lone pairs.

Answer 1

The Correct Option is C

Step 1: Understanding Saline Hydrides 
Saline hydrides (it{ionic hydrides}) are formed by alkali and alkaline earth metals with hydrogen. Examples: LiH, BeH$_2$, and MgH$_2$. These hydrides have a significant ionic character, though lighter ones like BeH$_2$ and MgH$_2$ have some covalent character. Thus, Statement I is correct. 
Step 2: Are Saline Hydrides Volatile? 
Volatility depends on weak intermolecular forces. Saline hydrides form strong ionic bonds, making them non-volatile. Thus, Statement II is incorrect. 
Step 3: Understanding Electron-Precise Hydrides 
Electron-precise hydrides like CH$_4$ and SiH$_4$ have enough valence electrons to form covalent bonds. These are not Lewis bases because they do not have lone pairs to donate. Thus, Statement III is incorrect. 
Step 4: Chromium Hydride Formula 
Chromium forms a hydride with the formula CrH. Thus, Statement IV is correct. Step 5: Correct Answer 
The correct statements are (I) and (IV). Thus, the correct answer is (C).