Among the following, the pair in which the two species are not isostructural, is
SiF4 and SF4
IO and XeO3
BH
PF and SF6
The helical structure of protein is stabilized by
dipeptide bond
hydrogen bonds
ether bonds
peptide bonds
The dipole moment of HBr is 1.6 × 10-30 cm and inter-atomic spacing is 1 Å. The % ionic character of HBr is
7
10
15
27
Which combination of atoms can form a polar covalent bond ?
H and N
H and Br
N and N
Na and Br
B.
H and Br
When there is less difference in electronegative of two atoms ( electronegativities are not same) difference in theirsize, polar covalent bond form.
(a) H and H:No difference in electronegativites, so form non-polar covalent bond.
(b) H and Br:Small difference in electronegativities and large difference in size. Hence, form polar covalent bond.
(c) N and N : Same electronegativity, so non-polar covalent bond.
(d) Na and Br:Large difference in electronegativities, hence electrovalent bond is formed.
Consider the following ions:
(i) Ni2+ (ii) Co2+ (iii) Cr2+ (iv) Fe3+
(Given, at. no. Cr = 24, Fe = 26, Co = 27, Ni = 28)
The correct order of magnetic moment of these ions is
(i) < (ii) < (iii) < (iv)
(iv) < (ii) < (iii) < (i)
(i) < (iii) < (ii) < (iv)
(iii) < (iv) < (ii) < (i)