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+ The halogens are a group in the periodic table that consists of five or six chemically related, elements: fluorine, chlorine, bromine, iodine (I), and astatine., , Halogens have 7 electrons In their outermost shell, The boiling points of halogens tend to move down the group due to the increasing strength, of van der Waals forces as the size and relative atomic mass of the atoms increase, Halogens are the only periodic table group containing elements in all three familiar states, of matter (solid, liquid, and gas) at standard temperature and pressure., Halogens are highly reactive, and they can be harmful or even fatal to biological organisms, in sufficient quantities., This reactivity is due to the high electronegativity and high effective nuclear charge., Halogens can react with atoms of other elements to gain an electron., , &- Additional Information, , + The elements of Group 2 include beryllium, magnesium, calcium, strontium, barium, and radium., These elements with the exception of beryllium are commonly known as alkaline earth, metals., , * These elements are called Alkaline Earth metals because of two reasons:, , Their oxides exist in the earth’s crust and are very stable to heat., , Their oxides and hydroxides show basic (alkaline) natures., , Beryllium fulfills the first criterion but not the second one since its oxides and hydroxides, show amphoteric behavior, rather than alkaline., , CaM Ae uy Parle], , Start Complete Exam Preparation, , SAR A eC, , | a) | ert eS Practice a a, Ee pele bole e ith & Quizzes, , B® Download App, , , , MCQ Question 2 View this Question Online, , The IUPAC name for the following compound Is:, , H,C_ 2 CH, , 1. 3-methyl-4-(3-methylprop-1-enyl)-1-heptyne, , 2. 3, 5-dimethyl-4-propylhept-6-en-1-yne
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3. 3-methyl-4-(1-methylprop-2-ynyl)-1-heptene, , 4. 3, 5-dimethyl -4-propylhept-1-en-6-yne, , Answer (Detailed Solution Below), , Option 4 : 3, 5-dimethyl -4-propylhept-1-en-6-yne, , Haloalkanes and Haloarenes MCQ Question 2 Detailed Solution, , lanation:, The IUPAC name for the following compound is 3, 5-dimethyl-4-propylhept-1-en-6-yne., , , , In the case of the double bond and triple bond, the position is the same and the position of, substituents is also the same, then the double bond is considered as senior so, the numbering starts, from a double bond., , CH,, 12 93 4 Be 7, H,C=CH—CH—CH—CH-C=CH, , CH, CH,, , CH,, , CH,, , 3, 5-dimethy-4-propylhept-1-en-6-yne
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+ Alkenes react with a solution of halogen and water to form halohydrins., , + Halohydrins are compounds having a hydroxyl group and a halogen group adjacent to each, other., , + When a mixture of Clp + H20 is taken, it forms hypohalous acids with general form X-OH, where X, is the halogen (here, Cl)., , * The halogen part gets a positive charge and behaves as an electrophile whereas the hydroxyl, group OH behaves as a nucleophile., , * The reaction takes place following Markownikoff's rule which states that: 'In an electrophilic, addition reaction of an unsymmetrical alkene with an unsymmetrical addendum (reagent), the, positive part of the addendum adds to the less substituted carbon and the negative part adds to, the more substituted carbon of the alkene., , + The general reaction is:, , H, , W" ~*~, , Zeus ~¥ CH,, CH,—CH=C. —+ CH;—CH= —+ CH,— CH—C—CH,, , a cu, Nes / cu, | |, , ci CI Cl CH,, cl, 7 H®, CH;—CH—C— CH,, Cl CH,, , Explanation:, , ‘ et Cl, + HO,, t However, the reaction CC1,CH = CH, +X does not take place by Markownikoff's, tule because of the presence of electron-withdrawing group Cl., , + The reaction proceeds via:, , cl, a #, of —cas CH, = CCl; —CH—CH,, cl OH—CI, , CCl, —CH —CH,OH, {, , + The positive part cl gets attached to the more substituted carbon and OH gets attached to the, less substituted part., + Hence, the product is:, , * & Additional Information, , + Kharash discovered that the addition of HBr to unsymmetrical alkenes in presence of organic, peroxides takes place against Markownikoff's rule., , + The more saturated carbon gets the positive part of the addendum whereas the less saturated, carbon atom gets the negative part of the addendum when an addition reaction of an, unsymmetrical alkane takes place in presence of peroxide. this is known as Anti, - Markownikoff's rule.