Which of the following compound possesses the C-H bond with the lowest bond dissociation energy?
Toluene
Benzene
n-pentane
2, 2-dimethyl propane
In the presence of HCl, H2S results the precipitation of group-2 elements but no group-4 elements during qualitative analysis. It is due to
higher concentration of S2-
higher concentration of H+
Lower concentration of S2-
Lower concentration of H+
C.
Lower concentration of S2-
Sulphides of group-II are precipitated by passing H2S gas through the solutions of cations in the presence of dilute HCi.
H2S being a weak electrolyte ionises only slightly while HCl being a strong electrolyte is almost completely ionsied.
H2S
Thus, the common ion effect takes place. As a result, the degree of dissociation of H2S decreases sufficiently and the concentration of S2- ions in the solution becomes very small, which results in the precipitation of those sulphdes having very low solubility product.
Which of the following is most likely to show optical isomerism ?
HC≡C--C≡CH
HC≡C--CH3
HC≡C--H
HC≡C-C (Cl) = CH2
Acetylene reacts with HCN in the presence of Ba(CN)2 to yield :
1, 1-dicyanoethane
1, 2-dicyanoethane
vinyl cyanide
None of the above
The following compound will undergo electrophilic substitution more readily than benzene:
nitrobenzene
benzoic acid
benzaldehyde
phenol
The correct statement about the compounds (a),(b)and (c) is :
(A) and (B) are identical
(A) and (B) are diasteromers
(A) and (B) are not enantiomers
(A) and (B) are enantiomers