chapter 12 group 17 elements.pptx

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1. Group 17 Made by: Muzammel Ezzat and Sulaiman Yaqubi Subject: Chemistry Teacher: Farid Gul Shinwari

2. 12.1   Physical properties of Group 17 elements 12.2   Reactions of Group 17 elements 12.3   Reactions of the halide ions 12.4   Disproportionation reactions Group 17: Halogens 2

3. 3 Group 17 elements Group 17 occupies the second column from the right in the periodic table and  contains F luorine (F ) Chlorine (Cl ) Bromine (Br ) Iodine (I ) Astatine (At ), T ennessine (Ts).

4. 4 What is group 17 on the periodic table called? Elements in group 17 in the periodic table are called the halogens. What are the physical properties of group 17 elements? These elements are nonmetallic in nature due to high ionization enthalpy. As molecular weight increases down the group, the density decreases . As we move down the group, the melting and boiling point increases.

5. 5 Reactions of group 17 elements The reactivities of the halogens decrease down the group ( At < I < Br < Cl < F). This is due to the fact that atomic radius increases in size with an increase of electronic energy levels . This lessens the attraction for valence electrons of other atoms, decreasing reactivity

6. What are halide ions A  halide ion  is a halogen atom having a negative charge. The halide  anions are fluoride (F − ),  chloride   ( Cl − ).

7. Reaction of the halide ions With fluoride or chloride ions Concentrated sulphuric acid isn't strong enough oxidising agent to oxidise fluoride or chloride ions. In those cases, all you get produced are the steamy fumes of the hydrogen halide - hydrogen fluoride or hydrogen chloride.

8. Disproportionation A species is simultaneously reduced and oxidised to form two different products. In general, the term disproportionation reaction can be applied to any desymmetrisation reaction of the following type: 2A → A’ + A”,

9. Disproportionation Example:  Phosphorous acid, when heated, undergoes disproportionation to produce phosphoric acid and phosphine: 4 H3PO3 → 3 H 3 PO 4  + PH 3

10. Thank You