Question

Match the terms in Column-I with their description in Column-II and choose the correct option:

	Column 1(Type of hydride)		Column II
A.	Electron	1.	MgH2
B.	Electron precise	2.	HF
C.	Electron rich	3.	CH4
D.	Saline Hydride	4.	B2H6

• A. A-4
• B. B-3
• C. C-1
• D. D-2

Answer 1

The Correct Option is C

To correctly match the types of hydrides in Column I with their descriptions in Column II, we need to understand the characteristics of each type of hydride:

1. Electron-deficient: These hydrides have fewer electrons available for bonding than the number required by the valence of the constituent atoms. Generally, they form multi-centered bonds. A common example is boron hydrides, like \(B_2H_6\). Hence, A corresponds to 4.
2. Electron-precise: These hydrides contain just enough electrons to form regular covalent bonds. Methane, \(CH_4\), is an example where carbon forms four single covalent bonds with hydrogen, thus satisfying valency. Therefore, B matches with 3.
3. Electron-rich: These hydrides have more electrons than needed for simple covalent bonding. The excess electrons reside as lone pairs. Water and halogen acids like \(HF\) are examples. Therefore, C aligns with 2.
4. Saline Hydrides (Ionic Hydrides): These are formed by the reaction of hydrogen with s-block elements (alkali and alkaline earth metals) and result in the formation of ionic compounds (metal hydrides). \(MgH_2\) is a classic example, which means D corresponds to 1.

Thus, matching each term to its appropriate description, we derive the correct pairing:

Column 1 (Type of hydride)	Column II
A. Electron-deficient	4. \(B_2H_6\)
B. Electron-precise	3. \(CH_4\)
C. Electron-rich	2. HF
D. Saline Hydride	1. \(MgH_2\)

The correct option is C-1 based on this categorization.