Question
Explain structure and bonding of diborane.
✓
Answer
- Electronic configuration of boron is $1s^2 2s^2 2p^1.$ Thus, it has only three valence electrons.
- In diborane, each boron atom is $sp^3$ hybridized. Three of such hybrid orbitals are half filled while the fourth $sp3$ hybrid orbital remains vacant.
- The two half-filled $sp^3$ hybrid orbitals of each $B$ atom overlap with $1s$ orbitals of two terminal H atoms and form four $B – H$ covalent bonds. These bonds are also known as two-centred-two-electron $(2c-2e)$ bonds.
- When $‘1s’$ orbital of each of the remaining two $H$ atoms simultaneously overlap with half-filled hybrid orbital of one B atom and the vacant hybrid orbital of the other $B$ atom, it produces two three-centred-two- electron bonds $(3c-2e)$ or banana bonds.
- Hydrogen atoms involved in $(3c-2e)$ bonds are the bridging $H$ atoms i.e., $H$ atoms in two $B – H – B$ bonds.
- In diborane, two $B$ atoms and four terminal $H$ atoms lie in one plane, while the two bridging H atoms lie symmetrically above and below this plane.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Half$-$life of $^{209}Po$ is $102 y.$ How many $\alpha -$particles are emitted in $1 s$ from $2 \ mg$ sample of $Po$?
→Explain the formation of alkyl halides from alkenes.
Calculate the mass percentages of H, P and O in phosphoric acid if atomic masses are H = 1, P = 31 and O = 16.
List the characteristic physical properties of the gases.
Classify the following as element and compound.
i. Mercuric oxide
ii. Helium gas
iii. Water
iv. Table salt
v. Iodine
vi. Mercury
vii. Oxygen
viii. Nitrogen
i. Mercuric oxide
ii. Helium gas
iii. Water
iv. Table salt
v. Iodine
vi. Mercury
vii. Oxygen
viii. Nitrogen
Collect the information on CNG and LPG with reference to the constituents and the advantages of CNG over LPG.
What are colloids? Explain.
Find the number of $\alpha$ and $\beta$ - particles emitted in the process ${ }_{86}^{222} Rn \longrightarrow{ }_{84}^{214} PO$
→What is an atom and molecule? What is the order of magnitude of mass of one atom? What are isotopes?
Write one point that differentiates nuclear reations from chemical reactions.