Question

Hello beautiful souls~
help me with these questions ​

Answer 1

#1

• Lewis acids can accept a pair of electrons for which their octet should be incomplete.

Lets take a compound of Boron .

• Take BF_3

Total bonded electrons=6(Incomplete octet)

• It requires 2 electrons .
• So it behaves as Lewis acid.

#2

You just need to observe the melting point and structure

• Diamond has carbon bonds in tetrahedral shape .
• where as graphite has bonds in hexagonal shape

So graphite has more boiling point.

• Therefore graphite is more stable

Answer 2

Step-by-step explanation:

As the number of valence electrons in boron is three, it forms compounds that are electron deficient. Such electron-deficient molecules tend to accept a pair of electrons to achieve stable electronic configuration and thus, behave as Lewis acids.

The correct answer is Graphite. The change in enthalpy of carbon in diamond to graphite form is negative. It shows that graphite should be more stable than diamond. The melting point of graphite is more than diamond which implies that it is a thermodynamically most stable allotrope of carbon.