Chemical Bonding and Atomic Structure MCQs for NEET — Chemistry Questions with Answers

(A). Due to smaller cation $BeC{l}_2$ is most covalent and is most stable in ether.

(A). The ionic character of the halides increases on moving down the group.

    $BeC{l}_2<MgC{l}_2<CaC{l}_2<BaC{l}_2$

(C). An ionic compound is soluble in water if its hydration energy > lattice energy.

(C). Due to greater polarisation by $L{i}^{+}$ ion, LiCl acquires some covalent character. Thus the ionisation of LiCl will be less than that of NaCl in water.

In B2H6, there is no direct boron-boron bond. The structure is not similar to that of C2H6 (ethane). The boron atoms are linked through hydrogen bridges, forming a bridged structure. The atoms are not in one plane. Therefore, the correct option is o3: the boron atoms are linked through hydrogen bridges.

${\mathrm{sp}}^3$-hybridisation, but four bonds are neither linear nor in one plane.

To form the dimer, the planar molecule has to assume a sort of tetrahedral orientation around the boron atom, as it happens in the case of Al2Cl6, which is the dimer of AlCl3 in the vapour state. But, in all the three boron halides, significant amount of pi-pi interaction occurs between the vacant p-orbital of boron and the filled p-orbitals of the halogens. Such interaction in the three trihalides increases in the order BBr3 < BCl3 < BF3

Borazole is polar due to $\mathrm{B}—\mathrm{N}$ bond; benzene is non-polar due to $\mathrm{C}—\mathrm{C}$ bonds.

Inorganic benzene is borazine, which has the chemical formula B3N3H6. It is an inorganic compound with a planar ring structure similar to that of benzene, but with alternating boron and nitrogen atoms instead of carbon atoms.

This give rise to net dipole moment zero in ${\mathrm{BF}}_3$. ${\mathrm{BF}}_3$ $\left({\mathrm{sp}}^2 \mathrm{hybridization}\right)$ ${\mathrm{PF}}_3$ $\left({\mathrm{sp}}^3\right)$.