Title HYDROCARBONS A-6.pdf ✅

CLASS : XIIth SUBJECT : CHEMISTRY DATE : DPP NO. : 6 2 (b) Markownikoff’s rule is for addition of unsymmetrical additive on unsymmetrical alkene. 3 (d) Paraffin wax are solid hydrocarbons from C20 to C30 atoms. 5 (d) Methane is called marsh gas because it is found in swamps or marshy places and can be obtained by bacterial decomposition of fossils of plants and animals. 6 (b) Among hydrocarbons, alkynes are easily oxidised. 7 (d) B.P. change with branching. 8 (f) These are few oxidants. 9 (a) The acidic character of H is, F—H > O—H >≡ C sp —H > N—H; H-atom attached on F, O, N and triply bonded carbon is acidic. 10 (b) CH3CH2CH = CH2 H2/Pd CH3CH2CH2CH3. 11 (c) Except acetylene, all terminal alkynes have only one acidic H-atom. 13 (d) These compounds are known as epoxy ethane or oxirane or cyclic ethers. 14 (b) According to X-ray analysis all carbon-carbon bond distance (1.397Å) are equal in benzene. The bond order of carbon-carbon bond is 1.5 in benzene. Hence, carbon-carbon bond distance (1.397Å) is less than C ― C single bond (1.54Å) and more than C = C double bond(1.33Å). Topic :-HYDROCARBONS CH2 CH2+ 1 2 O2 Ag CH2 CH2 O ; SOLUTION S
15 (c) Cracking involves decomposition of higher alkanes to lower one on heating. 16 (a) Follow mechanism of Wurtz reaction. 17 (c) CH4 is a constituent of bio-gas. 20 (a) The lowest temperature at which an oil gives sufficient vapours to form an explosive mixture with air is referred as flash point. It is 44C, 35C, 22.8C in India, France and England, respectively.
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. A B D D D B D D A B Q. 11 12 13 14 15 16 17 18 19 20 A. C C D B C A C C A A