NEET Chemistry: Class 11, Chapter 10: The p-Block Elements questions with solutions

Q1. Select the correct statement.

1. Carbon-carbon bond order in graphite is more than diamond
2. Carbon-carbon bond order in graphite is less than diamond
3. Hybridization of each carbon in diamonds is \( S p_{3} \)
4. Hybridization of each carbon in graphite is \( S p_{3} \)

Answer: Hybridization of each carbon in diamonds is \( S p_{3} \)

In diamond, each carbon forms four single bonds in a tetrahedral arrangement, which corresponds to sp3 hybridization. Graphite instead has sp2-hybridized carbons arranged in planar sheets with delocalized pi electrons.

Q2. Diborane \( \left(B_{2} H_{6}\right) \) reacts independently with \( O_{2} \) and \( H_{2} O \) to produce :

1. \( H B O_{2} \) and \( H_{3} B O_{3} \)
2. \( H_{3} B O_{3} \) and \( B_{2} O_{3} \)
3. \( B_{2} O_{3} \) and \( H_{3} B O_{3} \)
4. \( B_{2} O_{3} \) and \( \left[B H_{4}\right]^{-} \)

Answer: \( H_{3} B O_{3} \) and \( B_{2} O_{3} \)

Diborane burns in oxygen to form boron(III) oxide, while hydrolysis with water produces boric acid. So the two independent reactions give B2O3 and H3BO3, respectively.